Assessing the geotourism potential of glacial lakes in Plav, Montenegro: A multi-criteria assessment by using the M-GAM model

1 Introduction

As relatively popular areas within the geosciences, geoheritage and geoconservation are focused on recognizing, analyzing, and ensuring the long-term protection of valuable non-living natural features. Also known as geosites, these landforms have attained scientific, aesthetic, cultural, historical, and socio-economic values due to their recognition and use by humans [1,2]. They are generally made available for public access through sustainable geotourism strategies that emphasize educational potential and the conservation of geoheritage [3]. All efforts related to geoconservation and geotourism are fundamentally based on geodiversity, which represents the extensive range of Earth’s natural components and is often referred to as the foundation of geoheritage. Scientific literature related to geotourism typically includes disciplines such as geology, geomorphology, hydrology, soil science, mineralogy, and paleontology within the broader concept of geodiversity, highlighting their essential roles in supporting both human society and planetary systems [4].

The tourism valorization of geosites forms the foundation for the development of geotourism, a modern form of sustainable tourism based on visiting sites of geological heritage and natural geo-features. Geotourism is emerging as a specialized branch of tourism focused on the interpretation, promotion, and conservation of geoheritage through education and recreational activities [5]. It encompasses not only recreational aspects but also holds significant scientific, educational, ethical, and economic implications [6,7].

As a concept, geotourism includes all forms of tourism that involve visiting geologically important locations – such as glacial lakes, canyons, caves, and mountain ranges – with the aim of educating visitors and preserving natural assets [8]. In this regard, geotourism contributes to a broader societal goal: recognizing, valuing, and protecting geoheritage, thus ensuring the long-term sustainability of these areas [9].

A special role in contemporary geotourism is played by geoethics, a discipline that promotes responsible behavior toward the natural environment and geodiversity. A geoethical approach to planning and developing geotourism ensures the protection of sensitive geosites and promotes a moral obligation to preserve natural values for future generations. This is especially important in regions rich in geoheritage, such as northeastern Montenegro.

In the context of the municipality of Plav, geotourism can have a significant economic impact. The natural attractiveness of glacial lakes, mountain ranges, and geological phenomena of the Prokletije Mountains provides a strong basis for diversifying the local tourism offer. Geotourism opens opportunities for job creation, development of small businesses (guiding services, accommodation, local products), increased revenue from tourism taxes, and the promotion of sustainable local development. Moreover, geotourism contributes to the international recognition of Plav as a destination of geoheritage significance, strengthening its competitiveness on the tourism map of Montenegro and the Balkans.

The authors stress the importance of aligning geotourism initiatives with the Sustainable Development Goals (The Sustainable Development Goals, also known as the “Global Goals,” represent a universal call to action by the United Nations, adopted in 2015, urging all countries to work together to eradicate poverty, protect the environment, and ensure peace and prosperity for all people by 2030 at the latest.) and call for more targeted, practical strategies to bridge the gap between policy and implementation [10].

Montenegro is a country of remarkable natural diversity and richness, where a wide range of landscapes and natural attractions can be found within a relatively small area. Along the southern coast lie attractive Adriatic beaches surrounded by historic old towns, while just inland, high mountains rise sharply, concealing authentic villages, dense forests, and unspoiled wilderness. Among the most impressive natural areas in the mountainous part of the country is the Prokletije massif, considered one of the last preserved wild regions of Europe.

The main attraction of this area is its natural glacial lakes – Plav, Hridsko, Visitor, and Abdija Lakes – which are gaining increasing attention from visitors, nature lovers, and researchers due to their scenic beauty, geomorphological features, and ecological integrity. These lakes not only provide valuable insight into post-glacial landform development but also represent key elements of the region’s geoheritage. Despite their exceptional appeal and potential for niche tourism development, such as geotourism, these sites are still underutilized and lack proper promotion, infrastructure, and a coordinated conservation strategy. This study aims to highlight the significance of Plav’s glacial lakes for the sustainable development of geotourism, to protect these sensitive areas while enabling responsible tourism use.

A special focus will be placed on preserving the natural characteristics of these fragile ecosystems, alongside the promotion of sustainable management models that actively involve the local community and relevant institutions. In doing so, the glacial lakes of Plav have the potential to become a model for successfully integrating natural heritage with modern tourism flows, in line with the principles of sustainable development.

In Montenegro, significant scientific attention has been devoted to the glacial history of the Dinaric and Prokletije mountain ranges, and glacial lakes have been acknowledged as important components of these mountain environments [11,12].

Accordingly, this study applies the modified geosite assessment model (M-GAM) methodology to four glacial lakes within the municipality of Plav – Lake Plav, Visitor Lake, Hrid Lake, and Abdija Lake – with the aim of initiating a systematic evaluation of these features as geosites. The objective is to support their recognition and integration into strategies for sustainable geotourism development in northeastern Montenegro.

2 Materials and methods

2.1 Study area

The Municipality of Plav covers an area of approximately 328 km² and is located in the northeastern part of Montenegro, near the borders with Albania and Serbia. This mountainous region is characterized by complex terrain shaped through intense glacial, fluvial, and karstic processes. Evidence of glaciation, among the most pronounced in the Balkans, is clearly visible in the form of cirques, moraines, glacial valleys, and depressions. The Plav-Gusinje basin, the region’s most prominent glacial feature, lies above 900 m in elevation and is framed by terminal moraines through which the Lim River flows. The lowest point of the municipality is at 810 m above sea level (the confluence of the Zorićki stream with the Lim), while the highest peak, Bogićevica, reaches 2,358 m. Although the terrain is predominantly steep, mountain plateaus between 1,500 and 2,000 m provide more moderate slopes and favorable microclimatic conditions (Figure 1). One of the most valuable components of Plav’s geoheritage is its glacial lakes. Among them, Lake Plav, Hridsko, Visitorsko, and Abdijino are of particular significance due to their geological origin and natural integrity. Lake Hridsko and Lake Abdijino are located within the boundaries of Prokletije National Park and are under formal protection, which ensures the preservation of their geomorphological and ecological features. Lake Plav and Lake Visitorsko, while situated outside protected areas, remain key representatives of glacial lake systems in the Dinaric region. The monograph “Hydrological Route Plav” lists and locates 31 lakes within the territory of the municipality of Plav. The hydrological network of Plav encompasses numerous water resources, including larger and smaller watercourses, drinking water springs, mountain springs, and irrigation canals. The very fact that Plav is home to the largest glacial lake in the Balkans – Lake Plav – and the longest irrigation canal in Europe, “Bjelajka,” highlights the area’s water wealth and supports its epithet as the town with the richest hydrological network in Montenegro [42].

Figure 1

Presentation of geosites on the map of the Municipality of Plav.

2.1.1 Lake Plav

Lake Plav is the largest glacial lake in the Balkans. It is located in the municipality of Plav, at an altitude of 906 meters above sea level. In addition to offering excellent opportunities for sport fishing, the lake is suitable for swimming during the summer months, as well as for rowing and sailing. Its tributaries, the Ljuča River and the outflow into the Lim River, also make it an ideal location for kayak tourism. Lake Plav lies within the boundaries of the “Prokletije” National Park. The lake was formed at the end of the Würm glaciation, the last phase of the great Pleistocene glaciation, around 24,000 years ago, when water accumulated in a depression created by the Gusinje-Plav glacier. The shape of the lake resembles an irregular ellipse, elongated in a south–north direction, with a shoreline of approximately 7,520 m, which varies throughout the year depending on the lake’s water level. The lake is 2,160 m long, 1,490 m wide, with an average width of about 900 m. Its maximum depth is 9.15 m, while the average depth is 3.86 m. The lake covers an area of 1.99 km². Due to its geographical position, the lake is characterized by cold water temperatures, with monthly averages ranging from 2.8°C in January to 15.5°C in August [42,43,44,45,46,47,48,49,50].

2.1.2 Lake visitor

Visitor Lake is located at the source of the Murinska River, on the northwestern side of Mount Visitor, at an altitude of 1,735 m. The lake is situated about 2 km from the highest peak of Visitor. Surrounding the lake are forest species such as Molika pine and spruce. The lake was formed by the accumulation of water in the lowest glacial cirque on Visitor. On the northwestern side, the basin of this glacial lake is enclosed by moraine material, which is 25 m wide and rises 2 m above the lake’s surface. The lake’s maximum length is 91.5 m, its width is 72.5 m, the shoreline length is 294 m, the maximum depth is 4 m, and it covers an area of 4,212 m². Visitor Lake is fed by rainwater, snowmelt, several intermittent springs, and a small stream [42,43,44,45,46,47,48].

2.1.3 Lake Hrid

Hridsko Lake is located in the northwest part of the rocky mountains, specifically on Hridski Krš (2,358 m), at an altitude of 1,970 m, and is among the highest mountain lakes in the region. Surrounding the lake is a relic and endemic species of the beautiful Molika pine (Pinus peuce), also known as the “Pearl of the Balkans.” During the summer, the lake covers an area of 33,376 m², with a length of 295 m, a width of 175 m, and a maximum depth of 5 m. The shoreline is mostly rocky and slightly indented. The lake is fed by precipitation, snowmelt, and springs, while it loses water through underground outflow. In the summer months, the water temperature ranges between 16 and 18°C [42,43,44,45,46,47,48].

2.1.4 Lake Abdija

The lake is located in a cirque beneath the highest peak of Horolac and is notable for being situated at the highest elevation of any lake in Montenegro, at 2,054 m above sea level. The lake reaches a length of up to 50 m and a width of around 40 m, with a maximum depth of 4 m. It lies approximately 500 m from the state border with Albania and can be accessed via the Bjelajka summer pasture and the valleys of the Komarača and Treskavac rivers. Every year, the Tourism Organization of Plav organizes a summer hike to this geosite, offering nature lovers and tourists an opportunity for adventure along wild, untouched mountain trails that lead to the lake [42,43,44,45,46,47,48].

Together, these lakes represent essential elements of local geoheritage, offering insight into Pleistocene glaciation processes and post-glacial landscape evolution. Despite the high geotouristic potential of the area, current visitor statistics suggest underutilization. The lakes do not have regular, organized tourist tours from nearby towns. The only organized visits to these lakes are conducted by the Plav Tourist Organization, which organizes annual hiking trips to the lakes during the summer months, with approximately 100–150 participants attending these excursions.

The lakes lack additional tourist infrastructure, such as information boards in the town center and promotional photo and video materials, and there is insufficient promotion by local and national institutions, including the Municipality of Plav, the “Prokletije” National Park, and the National Tourism Organization of Montenegro. Currently, the only active promoter is the Plav Tourist Organization.

Overview and comparative analysis of tourist arrivals, overnight stays, and residence tax revenue in Plav from 2022 to 2024: In 2023, the municipality of Plav recorded 690 arrivals and 12,342 overnight stays, with a total of €4746.48 collected in residence tax. Compared to the previous year (2022), when there were 381 arrivals and 5,671 overnight stays, and only €878.64 collected in residence tax, a significant increase in all indicators is evident: the number of arrivals increased by 80.8%, the number of overnight stays by 117.6% and residence tax revenue grew more than fivefold.

In 2024, the Tourist Organization of Plav improved its system for recording tourist activity by introducing electronic registration and deregistration of foreign visitors, which contributed to more accurate statistics and more efficient collection of the residence tax. According to available data, in 2024, there were 1,252 arrivals and 14,391 overnight stays, while €6097.80 was collected from the residence tax. These results confirm a continued upward trend in tourism in Plav, with almost double the number of arrivals compared to 2022 and a steady growth in both overnight stays and revenue [50] (Figure 2).

Figure 2

Geosites: Glacial Lakes of the Municipality of Plav (a, Plavsko Lake; b, Visitor Lake; c, Hridsko Lake; d, Abdijino Lake). Note. Retrieved May 2, 2025, from https://www.plavto.me/turisticka-ponuda?kategorija=hidroloska-ruta.

2.2 Methods

The M-GAM model was applied to evaluate four glacial geosites in Montenegro with the goal of identifying their current status, advantages, and constraints in relation to the potential for geotourism. The M-GAM methodology relies on two primary categories of indicators: main values (MV) and additional values (AV). Within the MV category, there are three key components, while the AV category is composed of two. MV encompasses a total of 12 sub-indicators, and AV consists of 15. These indicators are represented through the following equations:

M − GAM = MV + AV

MV = VSE + VSA + VPr

AV = VFn + VTr

Here, VSE refers to scientific and educational value, VSA to aesthetic and scenic value, VPr to protection, VFn to functional aspects, and VTr to tourist-related value. The full structure and methodological background of the M-GAM model can be found in the publication by Tomić and Božić [28]. Survey participants rate the importance of each sub-indicator using a scale from 0.00 to 1.00. Based on these inputs, the average importance score (Im) for each sub-indicator is calculated. This Im value reflects how tourists perceive the relevance of each element within the assessment and is later multiplied by expert evaluations (ranging from 0.00 to 1.00) to derive the final score for each criterion [13].

The importance value is determined using the following formula:

m = ∑ k = 1 K Iv k K ,

where Iv _k denotes the individual rating provided by each participant and K is the total number of respondents.

To obtain the final values of MV and AV, the following expressions are used:

MV = Σ ( Im i × MV i ) ,

AV = Σ ( Im j × AV j ) .

As defined in the M-GAM methodology, the final value of each subindicator is calculated by multiplying the expert-assigned score by the average importance value (Im) derived from visitor responses. This approach allows for a more objective and comprehensive evaluation by incorporating both expert knowledge and tourist perception. Božić and Tomić [28] applied this method to assess geotourism segments in Serbia and calculated the Im values accordingly. The Importance factor for the Montenegrin geotourism market was calculated by Brđanin et al. [37]. For this research, the Im factor was adopted from previously mentioned research, to maintain consistency with the regional context of Montenegro. Table 1 presents the evaluation results for the 27 sub-indicators, as well as the Im values for Montenegro, which were obtained through a survey (Figure 3).

Table 1

Values of glacial geosites in plav according to the M-GAM methodology for Montenegro

Main indicators/subindicators	Geosites				Total value
	GS1	GS2	GS3	GS4	Im	GS1	GS2	GS3	GS4
MV
Scientific/educational value (VSE)
Rarity (SIMV1)	0.75	1.00	0.75	0.75	0.76	0.57	0.76	0.57	0.57
Representativeness (SIMV2)	1.00	1.00	1.00	1.00	0.75	0.75	0.75	0.75	0.75
Knowledge on geoscientific issues (SIMV3)	1.00	1.00	1.00	1.00	0.73	0.73	0.73	0.73	0.73
Level of interpretation (SIMV4)	0.75	0.50	0.75	1.00	0.74	0.55	0.37	0.55	0.74
Scenic/aesthetic (VSA)
Viewpoints (SIMV5)	1.00	0.50	0.75	0.75	0.83	0.83	0.41	0.62	0.62
Surface (SIMV6)	0.50	0.25	0.25	0.25	0.65	0.32	0.16	0.16	0.16
Surrounding landscape and nature (SIMV7)	1.00	1.00	1.00	1.00	0.90	0.90	0.90	0.90	0.90
Environmental fitting of sites (SIMV8)	1.00	1.00	1.00	0.10	0.78	0.78	0.78	0.78	0.78
Protection (VPr)
Current condition (SIMV9)	0.25	1.00	1.00	1.00	0.89	0.22	0.89	0.89	0.89
Protection level (SIMV10)	0.25	1.00	1.00	1.00	0.86	0.21	0.86	0.86	0.86
Vulnerability (SIMV11)	0.50	0.50	0.50	0.25	0.77	0.38	0.38	0.38	0.19
Suitable number of visitors (SIMV12)	1.00	1.00	1.00	1.00	0.76	0.76	0.76	0.76	0.76
AV
Functional values (VFn)
Accessibility (SIAV1)	1.00	1.00	1.00	0.25	0.79	0.79	0.79	0.79	0.19
Additional natural values (SIAV2)	0.75	1.00	1.00	0.50	0.76	0.57	0.76	0.76	0.38
Additional anthropogenic values (SIAV3)	0.50	0.50	0.50	0.25	0.74	0.37	0.37	0.55	0.18
Vicinity of emissive centers (SIAV4)	0.75	0.75	0.75	0.25	0.63	0.47	0.47	0.47	0.15
Vicinity of important road network (SIAV5)	1.00	1.00	1.00	1.00	0.76	0.76	0.76	0.76	0.76
Additional functional values (SIAV6)	1.00	0.50	0.00	0.00	0.71	0.71	0.35	0.00	0.00
Touristic values (VTr)
Promotion (SIAV7)	1.00	1.00	1.00	0.25	0.75	0.75	0.75	0.75	0.18
Organized visits (SIAV8)	1.00	0.25	0.25	0.25	0.64	0.64	0.16	0.16	0.16
Vicinity of visitors centers (SIAV9)	1.00	0.50	0.50	0.50	0.68	0.68	0.34	0.34	0.34
Interpretative panels (SIAV10)	1.00	0.75	0.25	0.00	0.81	0.81	0.60	0.20	0.00
Number of visitors (SIAV11)	0.25	0.25	0.25	0.25	0.61	0.15	0.15	0.15	0.15
Tourism infrastructure (SIAV12)	1.00	1.00	1.00	0.00	0.84	0.84	0.84	0.84	0.00
Tour guide service (SIAV13)	1.00	1.00	1.00	1.00	0.80	0.80	0.80	0.80	0.80
Hostelry service (SIAV14)	1.00	1.00	1.00	0.75	0.73	0.73	0.73	0.73	0.54
Restaurant service (SIAV15)	1.00	1.00	1.00	0.75	0.69	0.69	0.69	0.69	0.51

The importance factor (Im) for Montenegro represents the mean values ​​of all respondents, that is the values ​​are in bold. Im values ​​are further multiplied with values ​​by scientists in order to obtain final values, i.e. results for determining sub indicators.

Figure 3

Position of glacial lakes Plav on the M-GAM matrix.

The study was conducted during the period from October 2023 to March 2024, the survey was conducted through the online digital platform Google Forms, and it was anonymous. In the survey conducted to calculate the importance factor (Im) for Montenegro, a total of 365 respondents participated, of which 204 were female (55.90%) and 161 were male (44.10%). The majority of participants were from Podgorica – 142 respondents (38.90%), followed closely by Rožaje with 140 participants (38.35%). Bijelo Polje ranked third, with 18 respondents (4.93%). The remaining participants came from other cities across Montenegro, but with significantly lower percentages. Regarding the level of education, respondents were categorized as follows: primary school – 15 individuals (4.10%), secondary school – 83 individuals (22.73%), completed university studies – 155 individuals (42.46%), completed master’s degree – 87 individuals (23.83%), and doctoral degree – 25 individuals (6.84%). In terms of employment status, the majority of respondents were employed – 239 individuals (65.47%). They were followed by students – 62 participants (16.98%) – and unemployed individuals – 38 participants (10.40%) [37].

3 Results and discussion

For the purpose of assessing and evaluating the current state of geosites, specifically glacial lakes in the Municipality of Plav, an analysis was conducted to determine the present condition, identify advantages and existing infrastructural shortcomings, and assess the significance of these geosites for the further development of geotourism.

All four lakes were evaluated with very high ratings for scientific and educational values, with the geosite GS₄ Abdijino Lake standing out as the highest-rated with the score of 2.79. The other three sites have a slightly lower score for scientific and educational values (2.61). The highest scores among the scientific and educational value indicators (VSE) were awarded for representativeness (SIMV₂ = 1.00) and knowledge on geoscientific issues (SIMV₃ = 1.00), which were achieved by all four assessed glacial geosites – Plav Lake, Visitor Lake, Hridsko Lake, and Abdijino Lake. These maximum values confirm that all four sites are highly representative examples of glacial landforms and that they are well-documented and thoroughly studied in scientific literature. The lakes were formed in glacial cirques and illustrate characteristic geomorphological features shaped by Quaternary glaciation. This makes them ideal for geoscientific research and field-based education, providing accessible real-world examples for understanding glacial processes, paleoclimate interpretation, and geomorphological evolution in mountainous regions. In terms of rarity (SIMV₁), scores range from 0.75 to 1.00, with Visitor Lake receiving the highest score (1.00) due to the presence of a floating island, a highly unusual geomorphological feature at both national and regional scales. The other three lakes, although still considered rare (0.75), have more analogues in the region and thus are deemed slightly less unique. The interpretation level (SIMV) is highest at Abdijino Lake (1.00), reflecting the presence of organized hiking events, educational walks, and growing use of the site for outdoor learning, which enhances its accessibility to the public and its role in science communication. In contrast, the other sites have lower interpretation scores due to the lack of interpretive infrastructure such as information panels, guided tours, or educational signage, which limits their broader geotouristic and pedagogical value. Collectively, these indicators demonstrate that the evaluated lakes are highly valuable scientific and educational resources, capable of supporting both specialized academic inquiry and broader public engagement. They offer direct insights into glacial morphology and processes, and they represent important assets for developing field-based education, thematic tourism, and raising awareness about the geoheritage of Montenegro.

The landscape and aesthetic values of all geosites are of great significance, with the GS₁ Plav Lake standing out in particular, receiving a score of 2.83. Hridsko and Abdijino Lakes were evaluated with overall scores of 2.46, while Visitor Lake received a score of 2.25. All four glacial geosites exhibit notable scenic and aesthetic value, with Plav Lake (GS₁) standing out as the most visually prominent, receiving the highest score (2.83). Its large surface area, clear panoramic views, and harmonious integration within the Prokletije mountain landscape contribute to a strong visual identity and year-round appeal. The lake’s accessibility, recreational use, and reflection of surrounding peaks enhance its aesthetic experience. Hridsko Lake (GS₃) and Abdijino Lake (GS₄) follow with equal scores of 2.46, offering high-mountain aesthetics shaped by alpine terrain, elevation, and seclusion. Hridsko Lake, surrounded by coniferous forest and located at nearly 2,000 m altitude, presents a tranquil and pristine setting, while Abdijino Lake, the highest glacial lake in Montenegro, offers a dramatic, rugged cirque landscape with minimal vegetation, appealing to those seeking untouched natural beauty. Both are visually harmonious but limited by smaller surface areas. Visitor Lake (GS₂) received the lowest aesthetic score (2.25) due to its smaller size and lower viewpoint value, despite the presence of a unique floating island. Although integrated into a forested glacial basin, its limited openness and visual dominance affect its rating. Overall, while all sites are aesthetically valuable, Plav Lake’s expansive, accessible, and multifaceted landscape gives it a clear advantage in scenic evaluation.

The level of protection for these lakes is very specific because they are located within the protected zones of Prokletije National Park, except for Plav Lake, which lies outside the National Park zone and received an overall protection rating of only 1.57. The other three lakes were rated with exceptionally high scores, highlighting their great importance for continued conservation. At the same time, this makes some aware of great caution regarding further tourism development of these glacial lakes, as they could be damaged by excessive tourist visits and the construction of tourism infrastructure, which must be carefully managed.

The overall MVs are presented in Table 2, where the highest score was recorded for GS₃ – Hridsko Lake (7.99), which is widely recognized as one of the most beautiful and attractive glacial lakes in Montenegro. This high rating reflects its outstanding scenic/aesthetic qualities, well-preserved natural setting, and excellent scientific and conservation value, particularly due to its location within a national park and the pristine alpine environment surrounding it. In second place is GS₄ – Abdijino Lake (7.98), the highest-altitude glacial lake in Montenegro (2,054 m), valued for its excellent scientific representativeness, strong interpretive potential, and unique high-mountain landscape. The third-ranked site is GS₂ – Visitor Lake (7.75), which received slightly lower scores due to limited visual openness and interpretative infrastructure, though it still ranks highly because of its rarity (floating island) and high conservation status. GS₁ – Plav Lake received the lowest score among the four (7.01) in terms of MV; yet, this is still a very high score, reflecting its significance as the largest glacial lake in Montenegro, its educational value, and its scenic harmony within the landscape. The slightly lower MV score can be attributed to lower ratings in protection indicators, such as current condition and vulnerability, as well as moderate interpretation levels compared to other sites. Despite this, Plav Lake remains an essential geosite due to its geomorphological importance, accessibility, and multifunctional role in recreation, education, and conservation. The term geosites is used instead of geolocations as it more accurately refers to natural sites of geological significance that possess scientific, educational, ecological, and aesthetic values within geoheritage frameworks.

The difference between the main and AVs of these geosites is significant, with a noticeable weakness in functional and tourism values, especially at the GS₄ Abdijino Lake site, which received an overall score of 4.34. The low score for functional values of this glacial lake (1.66) is due to its great distance and poor accessibility. It can only be reached on foot, which creates a major challenge in organizing large tourist visits to the lake, as well as its considerable distance from major centers and important transport routes. The tourism values were rated with an overall score of 2.68, with organized visits and a guide service always available at this geosite (Table 2).

The other three geosites are characterized by exceptionally high ratings in terms of functional and tourism values. The geosite GS₁ Plav Lake, with an overall score of 9.76, represents an outstanding tourist potential for the development of geotourism in this region, both for Montenegro and the municipality of Plav. As the largest glacial lake in the Balkans, the lake is located in the very center, where the town of Plav has developed, along with additional anthropogenic values and proximity to major centers and important transport routes.

Although the assessed geosites received high scores in terms of MV, the indicators associated with touristic infrastructure and interpretive capacity, which carry a high weight in the context of sustainable geotourism development, reveal notable deficiencies. Key indicators such as the presence of visitor centers (SIAV₉), interpretative panels (SIAV₁₀), tour guide services (SIAV₁₃), actual visitor numbers (SIAV₁₁), and the proximity of hospitality and accommodation services (SIAV₁₄ and SIAV₁₅) are either completely absent or very limited in their physical presence across most of the evaluated sites. Plav Lake performs relatively well in this regard, benefiting from its proximity to the town of Plav, some basic infrastructure, and limited recreational services. However, Hridsko, Visitor, and especially Abdijino Lakes show a very low level of interpretive infrastructure and institutional support, which significantly restricts their tourism potential. The main reasons for this include difficult terrain accessibility, environmental protection restrictions (as many sites are located in or near protected areas), and a lack of strategic investment or integration into local development policies. Most of these sites are reachable only via long hiking routes, with minimal or no signage, and a lack of formal educational materials, which reflects a broader institutional gap in geosite management and interpretation planning. The absence of visitor centers, guide services, and interpretive signage limits the capacity of these geosites to engage the public in understanding glacial processes and the broader geoheritage context. Therefore, improving these indicators through the establishment of basic infrastructure, formal trail systems, trained guides, and interpretative materials should be a priority for enhancing the touristic and educational value of these geosites and realizing their full potential within the framework of sustainable tourism.

The Visitorsko and Hridsko Lakes sites were rated slightly lower compared to Plavsko Lake. Visitorsko Lake received an overall score of 8.56, with functional values rated at 3.50 and tourism values at 5.06. Hridsko Lake was rated with an overall score of 7.99, where functional values received a score of 3.33 and tourism values 4.66 (Table 2).

These geosites, specifically the glacial lakes, possess significant tourism potential and could become an important attraction for the municipality of Plav in the future. Accommodation and hospitality facilities, as well as guide services, are already available in the vicinity.

However, it is necessary to enhance promotional activities at the local level in order to achieve greater visibility in both national and international markets, especially considering that these geosites are perfectly integrated into the stunning natural landscape of the Prokletije mountains. Modern promotion strategies should include the use of digital marketing tools such as official websites, travel blogs, geotourism platforms, and mobile-friendly interactive maps. In particular, social media channels like Instagram, Facebook, TikTok, and YouTube offer powerful means for visual storytelling and real-time engagement with potential visitors. These platforms allow for showcasing the scenic beauty, outdoor experiences, and cultural context of the sites through short videos, reels, photo series, and influencer collaborations. Additionally, inclusion on international travel platforms such as TripAdvisor, Google Travel, Booking.com, and Airbnb Experiences could further promote these destinations and integrate them into the broader geotourism offer. Developing a consistent online presence with high-quality content, multilingual access, and geolocation tagging would significantly increase recognition, especially among ecotourists, hikers, and educational groups seeking unique nature-based experiences.

Geotourism has the potential to serve as a catalyst for sustainable development in small communities such as the Municipality of Plav. Despite its exceptional natural resources, Plav has experienced a noticeable decline in tourist arrivals over recent years. According to available data, the number of registered arrivals dropped from 1,074 tourists in 2018 to just 636 in 2023, suggesting either reduced visitor interest or inadequate registration systems. Similarly, the number of overnight stays declined from 12,634 to 10,821, resulting in decreased tourism expenditure and limited economic benefit for the local population. The majority of these visits are attributed to the diaspora, further highlighting the limited appeal of Plav to a wider tourist market.

The observed decline in officially registered tourist arrivals and overnight stays in the Municipality of Plav between 2018 and 2023 may not solely reflect a true decrease in visitation but rather point to underlying issues related to unregistered tourism activities and informal accommodation practices, commonly referred to as grey tourism. In many small and remote communities, including Plav, visitors, particularly members of the diaspora and domestic tourists, frequently stay in private homes, family-owned cabins, or unregistered rural lodgings that operate outside formal tourism channels and reporting systems. As a result, their presence is not reflected in official statistics, leading to a statistical underestimation of actual visitation rates. Additionally, the absence of a functional system for mandatory registration, combined with insufficient enforcement and limited institutional oversight, contributes to data gaps and the loss of potential tax revenue and economic benefits for the local community. This informal tourism model restricts the ability of local authorities to plan effectively, allocate resources, and invest in infrastructure or destination promotion. It also hinders efforts to position Plav as a competitive and sustainable geotourism destination, since reliable data is essential for attracting funding, partnerships, and broader market visibility. Addressing this issue requires coordinated efforts to formalize tourism services, raise awareness among local hosts, and implement regulatory mechanisms and incentives that support transparent and inclusive community-based tourism development.

In this context, geotourism emerges as a strategic avenue for reversing this negative trend. Plav is endowed with outstanding geoheritage, particularly in the form of glacial lakes – Plav, Hridsko, Visitor, and Abdijino – which are unique in Montenegro but have yet to be systematically evaluated in terms of tourism and nature protection. Applying the M-GAM methodology could provide a comprehensive and objective assessment of their scientific and touristic value, laying the groundwork for effective management, promotion, and conservation. The development of thematic georoutes, accompanied by interpretative signage and educational materials, could attract a new visitor demographic such as those interested in science, nature, and active recreation. In recent years, georoutes have gained increasing popularity across Europe and internationally as innovative tools for promoting geoheritage. They allow visitors to explore landscapes through a combination of physical activity, scientific interpretation, and cultural storytelling. Their appeal lies in the ability to connect multiple geosites into coherent and educationally rich experiences, often supported by digital applications, QR codes, and local guide services, making them particularly attractive to environmentally conscious and experience-driven travelers.

Beyond infrastructure development, a major challenge lies in the lack of trained personnel. Most local service providers do not speak foreign languages, and licensed tourist and mountain guides are scarce. Targeted training programs for the local population are essential to improving service quality and increasing employment. Promotion of geotourism potentials must align with sustainable development principles, including the protection of sensitive lake ecosystems and mountain landscapes.

Furthermore, the creation of both digital and printed promotional materials tailored to different visitor profiles is necessary to present Plav as a destination rich in geoheritage. Priority should be given to targeting educational tourists, environmentally conscious travelers, hiking and outdoor recreation enthusiasts, student groups, and amateur geoscience and biology learners, as these segments increasingly seek meaningful, nature-based experiences that combine exploration, learning, and sustainability. To effectively engage these target groups, collaboration with academic and research institutions from the fields of geosciences, biology, environmental protection, and tourism is essential. Such interdisciplinary partnerships can support the scientific valorization and popularization of local geosites and biodiversity hotspots through field education, ecological monitoring, joint research, and interpretative programming. The area’s rich glacial landscapes, endemic plant species, and diverse habitats provide ideal conditions for the integration of geo- and biodiversity-based tourism, enhancing both educational and conservation values. These efforts can also contribute to positioning Plav as a potential educational and field-study hub in the wider Balkan region. Given the ongoing decline in formally registered tourist arrivals and the local economy’s dependence on diaspora visits, geotourism represents a viable pathway to access new visitor markets and to build a distinct, sustainable tourism identity. By promoting the importance of both geoheritage actively involving the local community in its protection and interpretation, a foundation can be established for inclusive, long-term local development.

Geotourism does not rely on mass visitation, but rather on quality experiences – making it a development model well-suited to Plav’s capacities. Through a combination of scientific evaluation, local knowledge, and natural beauty, Plav holds significant potential to reverse the current tourism decline. Instead of stagnation, a strategically guided geotourism approach may lead to increased visitation, extended stays, and strengthened local economic resilience. Through a combination of scientific evaluation, local knowledge, and natural beauty, Plav holds significant potential to reverse the current tourism decline. However, this potential can only be fully realized through serious investment in promotion and the development of appropriate tourism infrastructure, which are far more crucial for attracting and retaining visitors than scientific value alone. While geoheritage provides a strong foundation, it is the visibility, accessibility, and overall quality of the visitor experience that ultimately shape tourism success. Well-designed infrastructures, such as marked geotrails, visitor centers, interpretative signage, and quality accommodation, combined with effective promotional strategies including digital media, travel platforms, and community-led initiatives, are essential for transforming Plav into a recognized and competitive destination within the nature-based and educational tourism market.

For future research, it is recommended to integrate advanced spatial analysis through geographic information systems (GIS) and multi-criteria decision analysis (MCDA) to enhance the mapping, evaluation, and management of glacial lakes as geoheritage sites. GIS would allow detailed spatial analysis of lake basin morphology, hydrological parameters, accessibility, and tourism infrastructure, while MCDA would facilitate the prioritization of development and conservation actions based on ecological sensitivity, aesthetic value, scientific significance, and geotourism potential.

In the previous period, an evaluation of the glacial lake geosites in Montenegro was carried out using the newly developed G-GAM methodology, introduced by Marković et al. [51]. The main feature of this methodology is the emphasized role of expert evaluation, with special attention given to the significance of each sub-indicator in the assessment process. For the purpose of calculating the Im G-GAM index, glacial values are assessed by experts in the fields of glaciology, glacial geoheritage, and glacial geomorphology. Within this study, the most significant glacial lakes of Montenegro were assessed, among which Plav Lake stands out as the largest glacial lake in the Balkans. According to the results of the G-GAM analysis, Plav Lake is strongly positioned as a tourist-attractive geosite (TV = 250.17), while its scientific–glacial value is somewhat lower (GV = 213.09). Nevertheless, it is classified in the same category (F33) as Crno Lake and Biogradsko Lake, which confirms its potential for geotourism development, particularly through improved promotion, interpretation, and protection measures [51].

A similar approach to lake assessment was applied by Somma et al. [52] in their study of Faro and Ganzirri lakes (Italy). These geosites, although of different genesis (tectonic–coastal lagoons), represent significant geoheritage examples due to their scientific rarity, cultural–natural linkages, and landscape attractiveness. They demonstrate a strong potential for geoeducation and geotourism but require careful planning to avoid degradation. Particularly, noteworthy is their potential future nomination as UNESCO natural heritage sites, which would further strengthen their status and level of protection. In comparison, Plav Lakes carry greater value as glacial models, while the Italian lakes are significant in the context of tectonic–coastal processes. Despite their different origins, both cases provide unique scientific insights and open opportunities for the development of diverse forms of geotourism.

Furthermore, Golfinopoulos et al. [53], within the framework of the Chelmos–Vouraikos UNESCO Global Geopark (Greece), presented Tsivlos Lake as a significant geosite. This lake, although of younger origin (formed after a landslide in 1913), already possesses a high degree of protection (Natura 2000, UNESCO) and developed tourism infrastructure, including georoutes, educational facilities, and strong promotion. With more than 75,000 visitors annually, Tsivlos has achieved international recognition and is fully integrated into the broader tourism system of Greece.

In contrast, the results of the assessment of Plav Lakes (Plav, Visitor, Hrid, and Ambijino) using the MGAM methodology indicate that this area possesses exceptional predispositions for geotourism development but is still not systematically valorized nor included in international protection frameworks. Although of different genesis, the Plav Lakes are characterized by outstanding aesthetic and landscape value, being situated within the Prokletije mountain range – one of the most impressive mountain systems of the Balkans. Their scientific significance lies in the opportunities for studying Quaternary glacial processes, which give them local, regional, and international importance.

A comparison between the Plav Lakes and Tsivlos clearly shows that the main difference lies in the level of research, institutional protection, and tourism integration. While Tsivlos is already established within the UNESCO system and represents an internationally recognized tourist attraction, the Plav Lakes remain in the background, lacking an adequate protection framework and developed infrastructure.

In conclusion, the Plav Lakes possess the potential to become the core of geotourism in Montenegro, similar to the role Tsivlos plays in Greece. Realizing this potential requires the systematic introduction of protection measures, the construction of tourism and educational infrastructure, and integration into international networks, including UNESCO geoparks. In this way, the valorization of the Plav Lakes would not only serve the purpose of scientific and tourism affirmation but would also contribute to the sustainable development of the local community and Montenegro as a whole.

4 Conclusion

This study emphasizes the untapped potential of geotourism as a strategic development model for the municipality of Plav, centered around its exceptional glacial lake geoheritage. The lakes – Plav, Hridsko, Visitorsko, and Abdijino – possess high scientific, aesthetic, and educational value, offering diverse opportunities for the creation of thematic geotourism routes and educational programs. However, despite their natural appeal, these geosites remain largely underrecognized and underdeveloped from a geotourism perspective. Key barriers include limited infrastructure, poor accessibility for some sites, lack of interpretative content, and insufficient engagement of the local population in tourism services. To address these issues, the implementation of geotourism must focus on sustainable and low-impact visitation, supported by targeted training for local guides, the development of interpretive signage, multilingual promotional materials, and partnerships with academic institutions. The application of GIS and multi-criteria analysis can further aid in identifying priorities for conservation and development.

The research brings several primary scientific contributions and novelties for the municipality of Plav, as well as for the initial development of geotourism in Montenegro. First of all, the MGAM methodology is presented as an innovative approach to the evaluation of geosites in the area of Plav. By applying this method, it has been possible to gain a more precise and comprehensive understanding of geosite values, taking into account scientific, aesthetic, touristic, and educational aspects. Another important contribution of this article relates to the results of the MGAM analysis, which provide clear guidelines for the strategic planning of geotourism development in Plav, the identification of priority geosites, and the creation of sustainable tourism products.

A particular significance of this research lies in the fact that it represents the initial phase of scientific studies on glacial lakes in the municipality of Plav. Until now, these lakes have mainly been recognized through their landscape and aesthetic value, while this study has made the first step toward their systematic evaluation from the perspective of geotourism. This opens the way for further interdisciplinary research, which can contribute not only to the development of a scientific database on geoheritage but also to the creation of sustainable tourism offers that will position Plav as a recognizable geotourism destination in Montenegro and the wider region.

The practical value of the results of this research lies in their direct applicability in tourism planning and development in the municipality of Plav. The MGAM methodology, through a clear ranking and evaluation of glacial lakes and other geosites, provides the basis for identifying the most attractive and promising locations for the development of a geotourism offer. In this way, the local government and tourism organizations can direct resources toward improving access roads, building educational infrastructure (information boards, trails, viewpoints), and creating interpretive content that will bring visitors closer to the natural and geological values of the area.

For the municipality of Plav, these results provide a strategic foundation for differentiation in the tourism market – instead of relying only on traditional forms of tourism, Plav can develop a new type of tourism, namely geotourism, which promotes its unique glacial lakes and mountain landscapes. At the same time, this encourages sustainable development, as the emphasis is placed on the preservation of natural resources and their presentation through education, visitation, and experience, rather than through mass exploitation. In the long run, such an approach can generate new economic benefits for the local population through the development of accommodation facilities, guided tours, local products, and cultural events connected to natural heritage.

Ultimately, geotourism in Plav can enhance visitor experiences, promote community-based tourism, protect sensitive ecosystems, and establish Plav as a leading destination for nature-based and educational travel in Montenegro.