Chelmos Vouraikos UNESCO Global Geopark: Links Between Geological and Landscape Diversity with Biodiversity in the Context of Geotourism

Abstract

Chelmos Vouraikos UNESCO Global Geopark is located in North Peloponnesus, Greece. As a member of the Global Geoparks Network, it is valued for its rich geoheritage in combination with its natural and cultural wealth. Several different landforms of international value are located in the area. The scope of this work is to present an overview of its geomorphological features, link them with biodiversity and highlight their value for geotourism. Its geology is complicated due to intense tectonism. Three geotectonic units of the Alpine Orogeny can be found along with post-Alpine sediments related to the Corinth Gulf rifting. The area is highly covered by limestone creating important karst landforms. High peaks surround river valleys and deep gorges create breathtaking landscapes. Some of them cut through high and steep conglomerate slopes. Remnants of past glaciation have been preserved on Mt Chelmos. The exceptional geodiversity of the area is linked with rich vegetation and high endemism. The many identified geomorphological sites highlight the Geopark’s strong commitment to geomorphology and its importance as a key geomorphological destination. Highly visible geomorphological sites with ecological value can also promote environmental awareness and contribute to the protection of biodiversity.

1. Introduction

For the past two decades, there has been a growing global recognition of the significance of geomorphological heritage, particularly in relation to its potential for geotourism development and its role in conservation efforts. Geomorphological heritage acquires its value through its expanding recognition as a sustainable territorial resource, a role further strengthened by initiatives such as geotourism and environmental education [1]. The significance of geomorphology as a form of heritage stems from its role as the foundational structure for habitats and landscapes, underpinning both human lifestyles and cultural traditions, while maintaining a lasting presence on the Earth’s surface [2].

UNESCO Global Geoparks (UGGps) are globally designated protected areas that include either multiple geosites of international geological significance, regardless of scale, or a diverse collection of geological features noted for their scientific value, rarity, or esthetic appeal. Geosites with geomorphological interest can be recognized as both natural and tourism assets, offering notable economic advantages, particularly when found within protected areas. (Ref. [3], among others).

These sites attract various visitor groups, including hikers, tourists, and educational travelers, who seek meaningful engagement with the natural landscape. However, despite their familiarity with local populations, the cultural and ecological significance of these landforms is frequently overlooked or undervalued [2]. There are characteristic examples, where geosites with geomorphological interest were used for geotouristic reasons, combining ecological and cultural values. In Sweden, the Blenio-Lucomagno region National Park emphasized the connection between geomorphology and biodiversity and the Trient Valley, where cultural and tourism-related aspects were taken into account, links landforms to local heritage and promotes them through eco-tourism initiatives [4].

As noted by Zouros [3], Greece’s complex geological and geomorphological history, combined with its diverse climatic conditions, numerous islands, and deeply indented coastline, has shaped an exceptional diversity of natural landscapes. This abiotic richness, alongside a mosaic of microclimatic zones, sustains a remarkable variety of flora and fauna and supports a wide range of ecosystems. Greece’s dynamic geological and geomorphological evolution has also contributed to the formation of numerous geosites with geomorphological scientific significance. Several prominent geosites with important geomorphological features, including Meteora (Pili-Meteora UGGp and UNESCO World heritage Site), Mount Olympus (World UNESCO Biosphere Reserve), the Samaria Gorge in Crete (National Park and World UNESCO Biosphere Reserve, the Vikos and Aoos gorges in Epirus (Vikos-Aoos UGGp), the Diros Caves in Peloponnesus, etc. are well-known tourist destinations attracting thousands of visitors annually.

Study Area

Chelmos Vouraikos UGGp is located in N. Peloponnese, Greece, 100 km from Patras city and 200 km from Athens. It occupies an area of 647 km². The population inhabiting the geopark area is around 7000 people. It has been a member of the European Geoparks Network (EGN) and the Global Geoparks Network (GGN) since 2009 and under the auspices of UNESCO as an UGGp since 2015. Its major elements of interest include significant geodiversity, impressive landscapes, notable flora and fauna, as well as remarkable and unique historical and mythological elements and local tradition. The scope of the Chelmos Vouraikos UGGp, is the preservation, protection and proper management of the geodiversity and biodiversity of nature and the landscape being part of a natural heritage of national and international importance. Chelmos Vouraikos has also been a National Park since 2009.

The geopark area has a rich geoheritage depicted in its various rocks that have been formed in 11 different geologic periods and describe the story of the Earth’s development at this part of the world through time, especially of those internal and external processes that have shaped it. Within the territory of the geopark 43 geosites have been established so far (

Table 1. List of geosites of the Chelmos Vouraikos UGGp and their characterization. Tectonic = T, Lithological = L, Stratigraphical = S, Karstic = K, Geomorphological = Gm, Hydrological = H, Geotechnical = Gt, Palaeontological = P.

ID	Geosite	Category
1	Niamata	T, L, S
2	Portes—Triklia	K, L, T
3	Mamousia—Rouskio	L, S
4	Trapeza Marine terrace	Gm, T
5	Kerpini Conglomerates	L, Gm
6	Roghi	L, S
7	Tectonic graben Kalavrita	T, Gm
8	Agia Lavra	T
9	Xidias Lignites	L, S
10	Priolithos	L, S
11	Cave of the Lakes	K
12	Mavri Limna	Gm, T
13	Lousoi sinkhole	K
14	Aroanios Springs	K
15	Mati tou Ladona	K
16	Vesini radiolarites	L, S
17	Doxa lake	H, Gt, L
18	Solos	L
19	Tsivlos Lake	H, Gm
20	Water of Styx	Gm, S, K
21	Xerocambos breccias	Gm, L
22	Feneos sinkholes	K
23	Lousoi polje	K
24	Mavrolimni	Gm
25	Analipsi	L, K
26	Valvousi	K, Gm
27	Keramidaki	L, T
28	Mega Spilaio	Gm, L, P
29	Kastria spring	K
30	Spanolakkos	Gm, L
31	Palaeochori lignites	P, L
32	Valimi landslide	Gm
33	Pausanias Vine	L
34	Psili Korfi	Gm, T, K
35	Ntourntourvana	Gm, S, P, K
36	Chelonospilia	Gm
37	Madero	Gm, S
38	Eroded Conglomerates	Gm, L
39	“Balcony” of Styx	Gm, S
40	Tessera Elata	Gm, L
41	Vouraikos Delta fans	L
42	Kalavryta Castle of Orias	Gm
43	Petrouchi	Gm

). All of them are designated with informative signage and used for geotourism. Nineteen of them have acknowledged scientific importance and 12 are used for educational purposes. Additionally, nine of them bear an internationally recognized value (Special Protection areas-SPA and Sites of Community Importance (SCI)). A high number of the assessed geosites of the geopark (21) have been characterized as having a primarily or secondarily geomorphological value (Table 1). In the geopark‘s territory there are also several sites of archeological, natural and cultural interest that are included in the geopark’s sites of interest.

The scope of this work is to briefly present and depict in a simplified way the different geomorphological features that can be found in the area of Chelmos Vouraikos UGGp, link them with biodiversity and culture and highlight their value for geotourism.

2. Important Features of Geodiversity and Biodiversity of Chelmos Vouraikos UNESCO Global Geopark

2.1. Geology of the Geopark

Within the area of the Chelmos Vouaikos UGGp, three distinct geotectonic zones are present: the Tripolis Zone, the Pindos Zone, and the metamorphic formations of the Phyllites–Quartzites series. In addition, Neogene and Quaternary post-Alpine sediments—including conglomerates, marls, sandstones, lignites, sands, and muds—along with Holocene alluvial deposits, have accumulated in the more recent basins. (Figure 1).

The Tripolis Zone is primarily composed of Upper Triassic to Upper Eocene neritic limestones and dolomites [6]. These rocks are mainly distributed in the east-southeastern part of the geopark, occurring on Mount Chelmos, along the Krathis River, and in certain sections of the Vouraikos Gorge. Beneath this unit lies the Upper Palaeozoic to Lower Triassic volcano-sedimentary Tyros Formation, which features alternating layers of phyllites, shales, limestones, dolomites, sandstones, and volcanic rocks. This formation exhibits a very low degree of metamorphism and forms the substrate of the Tripolis Zone. The carbonate sediments of this zone were deposited in shallow marine environments continuously throughout the Mesozoic and up to the Upper Eocene. Deposition of flysch—comprising alternating sandstone and marly layers—began during the Upper Eocene and continued until the end of the Oligocene. Stratigraphically, the formations of the Tripolis Zone underlie the Pindos Zone and the post-Alpine formations, while they are themselves thrust over the Phyllites–Quartzites Series.

The rocks of the Pindos Zone occupy most of the geopark’s area, particularly in its western and southern parts. The Middle Triassic Priolithos Formation is composed of clastic sediments that underlie the Upper Triassic to Lower Jurassic limestones of the Drymos Formation. Above these, the Upper Jurassic to Lower Cretaceous Radiolarites Formation (sensu lato) consists of pelites, radiolarites, and limestones. This is followed by the Albian to Cenomanian “First Flysch” Formation, characterized by clastic layers. During the Upper Cretaceous, thin to moderately bedded pelagic limestones were deposited, which gradually transitioned into flysch during the Upper Maastrichtian to Eocene period. Since the Late Eocene, the Pindos Zone has been overthrusted westward onto the Tripolis Zone. Its highly folded rock masses form a tectonic nappe made up of several upthrusted blocks [7,8].

The Phyllites–Quartzites Series appears along the tectonic window of Mount Chelmos. Within the geopark, this unit is visible in the upper reaches of the Krathis River and across the Feneos plateau (polje). The rocks are strongly metamorphosed under high-pressure and low-temperature conditions [9,10]. The lower portion of the series consists mainly of schists, while the upper part is composed of phyllites and quartzites. Zircon dating indicates a Lower Palaeozoic age [11] making these the oldest rocks within the geopark area.

The post-Alpine formations extend in a WNW–ESE direction, parallel to the Corinth Gulf to the north, forming successions up to about 2.8 km thick [12]. These Neogene basins developed upon the Alpine basement as a result of the secondary extensional tectonics of the western Aegean system, which led to the formation of the Corinth Gulf Rift following the subduction of the African Plate. Today, the Corinth Rift is regarded as the most seismically active zone in Europe [13]. Since its initiation around 4–5 million years ago, this rifting has controlled the tectonic and geomorphological evolution of northern Peloponnese [14,15], including the northern sector of the geopark. Five major north-dipping normal faults—Kalavryta, Kerpini–Tsivlos, Doumena, Pirgaki–Mamoussia, and Helike [12]—define the structural framework of the region. These faults bound four main basins and create a series of approximately WNW–ESE-oriented, north-dipping, rotated fault blocks related to the regional N–S extensional regime [13]. The resulting half-graben structures were filled with syn-rift Pliocene and Quaternary deposits resting unconformably on the basement [16]. These blocks were uplifted [16] with displacements reaching several hundred meters [13]. As deformation progressively migrated northward, tectonic activity diminished in the older basins [12]. Throughout this period, the uplifted footwalls were deeply incised by north-flowing rivers such as the Vouraikos, Ladopotamos, and Krathis.

The syn-rift deposits within the geopark were accumulated in three distinct phases [12] corresponding to the three lithostratigraphic groups defined by [17] and [18], Lower, Middle and Upper.

• Lower Group (Phase 1: 4–1.8 Ma; [12]): Deposited in the half-graben basins of the Kalavryta, Kerpini–Tsivlos, and Doumena fault blocks, these formations consist of alluvial, fluvial, and lacustrine deposits, including massive conglomerates (Kalavryta and Mega Spilaio Formations), alternating marls and muds, and interbedded lignite layers [13,19]. Northward, these successions transition laterally into finer-grained sediments.
• Middle Group (Phase 2: 1.8–0.7 Ma; [12]): Formed within the Pirgaki–Mamoussia half-graben basin, these deposits consist of thick, coarse-grained conglomerates representing Gilbert-type fan deltas with lagoonal deposits at their base [13,19].
• Upper Group (Phase 3: 0.7–0.4 Ma; [12]): Accumulated in the Helike half-graben basin, these sediments include marine terraces, fluviolacustrine and lagoonal deposits, and small Gilbert-type fan deltas [13,19].

Additionally, around and atop Mount Chelmos, moraines, glacial breccias, cirques, and alpine lakes provide clear evidence of glaciation during the Middle and Late Pleistocene [13,20].

2.2. Vegetation and Flora of the Geopark

The natural vegetation of the Chelmos Vouraikos UGGp [21] reflects the combined influence of multiple factors—chiefly its diverse orographic relief, the petrological and geological composition of its soils, prevailing bioclimatic conditions, and long-standing human activity that has shaped the landscape since antiquity. These interactions have produced a complex contemporary land-use mosaic, encompassing both natural and semi-natural ecosystems influenced by traditional practices (notably in remote oromediterranean, or so-called “alpine,” zones), as well as ecologically, historically, and culturally significant landscapes [22]. The geopark’s natural ecosystems are primarily composed of woodlands and forests scattered all over the geopark area and dominated by Pinus halepensis (mostly at the northern part of the geopark around geosites 03-Mamousia-Rouskio and 04-Trapeza Marine Terrace), Pinus nigra (e.g., around geosite 19-Tsivlos Lake) and the Greek endemic fir Abies cephalonica (the most characteristic presence in geosites being at the geosites 26-Valvousi, 35 Ntourntouvana and 17-Doxa Lake, 39-Styx Balcony and 40-Tessera Elata), along with Quercus coccifera, Q. pubescens, Q. frainetto woodlands, and riparian galleries of Platanus orientalis and Salix alba (most representative presence in geosites, at the geosites 14-Aroanios springs, 15-Ladon’s springs and in Vouraikos gorge). In the case of Abies cephalonica montane forests, the underlying geology (e.g., limestone and flysch) and steep terrain result in shallow soils and cooler, moister microsites that favor fir establishment. Similarly, fluvial landforms play a key role in shaping and stabilizing riparian woodlands [23]. In addition, extensive areas of low and high scrub vegetation—evergreen sclerophyllous scrublands, garrigues, and phrygana—occur at lower and mid-elevations (more characteristic example within geosites being geosite 1-Niamata and other sites in the Vouraikos gorge), while rock and scree communities and oromediterranean grasslands dominate higher altitudes (more characteristic examples within geosites being the Neraidorachi plateau of Chelmos along with the geosite 34-Psili Korfi, the geosite 21-Xerocambos breccias, the area around the geosite 20-Water of Styx and the geosites 28-Mega Spilaio and 38-Eroded Conglomerates). The distribution of garrigues and phrygana is closely tied to geological and geomorphological factors: they typically develop on shallow, rocky substrates and exposed slopes or terraces where limited soil development and high erosion rates favor scrub over forest growth [24]. Rock and scree vegetation, on the other hand, is governed by rock type, weathering patterns, slope angle, and rockfall dynamics. The continuous renewal of the substrate and thin soils restrict vegetation to highly specialized species adapted to unstable, nutrient-poor environments [25]. Overall, the area supports eight MAES level 2 ecosystem types [26,27,28,29] encompassing 16 habitat types [30]. Two of these—(i) 6230 “Species-rich Nardus grasslands on siliceous substrates in mountain (and submountain) areas” (e.g., around geosite 20-Water of Styx) and (ii) 9530 “(Sub-)Mediterranean pine forests with endemic black pines” (e.g., around geosite 19-Tsivlos Lake)—are recognized as priority habitats for conservation within the European Union [31].

Chelmos Vouraikos UGGp is also a major biodiversity hotspot for Greek flora and forms part of the endemism center of the northern Peloponnesian mountain ranges [32,33,34]. The area hosts more than 1100 plant taxa, including over 120 Greek endemics, 25 Peloponnesian endemics, and six local (geopark) endemics: Alchemilla aroanica, Corydalis blanda subsp. oxelmannii, Lonicera alpigera subsp. hellenica, Polygala subuniflora, Silene conglomeratica, and Valeriana crinii subsp. crinii. Especially the endemic species Silene conglomeratica is only found around geosite 28-Mega Spilaio and is closely connected to the conglomerate steep slopes and the high altitude of the site. Many of these endemic taxa are listed in IUCN threat categories, while Globularia stygia is designated a priority species for conservation under Annex II of the EU Directive 92/43/EEC [31], further underscoring the ecological importance of the geopark’s mountainous landscapes. As noted by [35], biodiversity hotspots within the protected area coincide spatially with zones of high geodiversity, particularly Mount Chelmos and the Vouraikos Gorge. For example, around geosite 20-Watet of Styx on Chelmos Mountain, five of the local endemic plant species can be found.

The geopark also harbors a notable number of aromatic and medicinal plants—such as the Peloponnesian endemic ironwort (Sideritis cladestina subsp. peloponnesiaca which exists around geosite 35-Ntourntouvana), sage (Salvia officinalis) (e.g., in Vouraikos gorge), and horse mint (Mentha longifolia) [36] highlighting its significance for ecosystem services that link biodiversity with local cultural traditions, economy, and heritage [37]. This exceptional floristic richness is closely tied to the diversity of geological substrates, exemplified by the identification of 43 distinct geosites.

3. Methodology

With the aim of a thorough presentation of the main geomorphological elements of Chelmos Vouraikos UGGp which show an increased geotouristic interest, the geopark area was divided into six geographical parts (Vouraikos Basin, Krathis river area, Kalavryta Basin, Loussoi karstic system, Mt Chelmos, Feneos valley and the South part of the geopark), each showing specific geomorphological features. These units were identified through a combination of systematic field observations and bibliographic reference review. A topographic map was generated using ArcGIS Pro Advanced 2.5 software. The map incorporates a Digital Elevation Model (DEM) from the Copernicus program, the primary river channels within the geopark, significant mountain peaks referenced in the study and towns/villages of the geopark area. Geomorphological maps (either using the topographic map or satellite images) were prepared for the main units depicting key geomorphological structures (with significant geotouristic role).

The categorization and assessment of the geosites of Chelmos Vouraikos UGGp has been carried out by [5] using the methodology of [38]. Throughout this manuscript the term “geomorphological sites” is used when referring to the geosites of Chelmos Vouraikos UGGp that fall in the geomorphological category (Table 1). The results of [5] regarding the geomorphological geosites have been used in order to assess the importance of these geosites for geotourism and biodiversity.

4. Results

4.1. Landscapes and Landforms in the Area of the Geopark

The topography of the study area is mainly mountainous, and is covered by a variety of vegetation types, traversed by rivers and streams (Figure 2). Among the peaks with altitudes above 2000 m a.s.l., Psili Korfi is the highest of the mountainous region with an altitude of 2355 m a.s.l., at Mt Chelmos.

The area of the geopark is presented in this work in six geographical parts that show common geomorphological features (Figure 2). These parts are presented from the north to the south as following: Vouraikos Basin, Krathis River area, Kalavryta Basin, Loussoi karstic system, Mt Chelmos, Feneos valley and the South part of the geopark.

4.1.1. Vouraikos Basin

Vouraikos River flows for 46 km from Priolithos to Diakopto and finally to the Corinth Gulf, which is one of the most tectonically and seismically active regions worldwide [39,40]. The drainage area of Vouraikos River (namely the Vouraikos Basin) covers 284 km² [41]. Within Vouraikos Basin, several distinct landforms are met (the most important being a V-shaped valley, namely the Vouraikos Gorge, a U-shaped valley and a knickpoint, Figure 3) owing their unique existence to an intensely diverse relief. The landscape of the area has been formed by a combination of factors. A complex geological background triggered by intense tectonic activity and climatic processes have affected the shape and size of Vouraikos Basin [42]. As a result, Vouraikos gorge has been formed and dominates the landscape. Odontotos Rack Railway has been constructed along the gorge, as the gorge provided an easy route for it. Odontotos Rack Railway was the main transportation way for the people of the geopark in the past, while nowadays it attracts many tourists and gives them the opportunity to admire the incredible geomorphology, and the unique floristic elements and vegetation/habitat types of the gorge. The vegetation of Vouraikos River gorge is directly correlated with the geomorphology of the site, as well as with its specific geological structure. More precisely, the riparian galleries of Platanus orientalis and Salix alba are the dominant vegetation types at the riverbanks of the gorge, while chasmophitic vegetation types containing a high percentage of Greek endemics covers the siliceous and conglomerate cliffs. Several geomorphological features, such as a knickpoint coinciding with geosite 02-Portes-Triklia (Figure 4), conglomerate cliffs coinciding with geosite 05-Kerpini conglomerates, geosite 28-Mega Spilaio, and alluvial and delta fans (e.g., geosite 42-Vouraikos Delta Fan) can also be found [42].

The morphology of the area results, amongst other factors, from the alternation of rocks of different hardness. More specifically, in the area appear thin bedded limestones and flysch (cherts and red siltstones) of Pindos zone, thick bedded limestones of Tripolis zone, flysch (siltstone and sandstone) and finally highly cemented conglomerates (Figure 1). Talus cones and soil formations also exist [43].

The Southern margin of the Corinth Rift exhibits an impressive array of north-dipping normal faults active at least since the Middle Pleistocene [12,15,44,45,46]. Heliki Fault (especially its eastern part) crosses the Vouraikos River approximately 2 km from its mouth [47,48]. As a result, marine sediments that were deposited during phase 3 (0.7–0.4 Ma [12]) due to climate variations, were uplifted in the area of the fault‘s footwall and consist nowadays of the very well-known Trapeza marine terraces (Geosite 4, Figure 2) exposed at the northern border of the geopark (Figure 3). On the flat area that has been created, Trapeza village, with an extraordinary view of the Corinth Gulf, has been built.

On the hanging wall of East Heliki fault, the Vouraikos canyon is divided into three geomorphological segments, A, B and C (Figure 3). Downstream a high-relief, highly incised valley can be noticed (segment A). The river erodes the cemented Vouraikos Gilbert-type delta fan conglomerates (Geosite 42, Figure 2) for hundreds of meters (over 800 m thick) and forms a characteristic U-shaped valley. These sediments were deposited during the Calabrian (about 1 million years BP), in a sea body with a depth of 300–700 m [49].

Between 7 and 16 km from the fault a very narrow bedrock gorge is formed and constitutes the knickzone of the Vouraikos River (segment B, Figure 3). Portes-Triklia (Geosite 2, Figure 2 and Figure 4) and Niamata tectonic window (Geosite 1, Figure 2) geosites depict the incredible combined effect of erosion and tectonics. This part of the gorge exhibits very high slopes due to the intense tectonics, making it impossible for a train to climb. This forced the construction of the racks of the Odontotos railway. The uplift along the Portes–Niamata area is controlled by two opposing faults that led to the rising of the compact and erosion-resistant alpine sediments of Pindos and Tripolis zone described above (Figure 1). The continuous deep erosive action of the water of the Vouraikos River, along with continuous rising, have led to the formation of this impressive geomorph from the surficial dissolution of the limestone [50]. This site is also of extraordinary floristic importance due to the presence of rare endemics, such as Asperula arcadiensis, Aurinia moreana, Colchicum peloponnesiacum, Dianthus mercurii, Dichoropetalum achaicum, Stachys parolinii and Teucrium halacsyanum.

The remaining highly cemented riverine to lacustrine conglomerates rise up steeply alongside the river and form impressive landforms. The Mega Spilaio (Figure 5), Kerpini (Figure 6) conglomerates, Eroded Conglomerates and Petrouchi (Geosites 28, 5, 38 and 43, respectively, Figure 2) geosites constitute characteristic examples of these formations. Especially the Mega Spilaio conglomerates have been formed during phase 1 (4–1.8 Ma; [12]) as alluvial fan deposits. Their riverine origin is highlighted by the existence of fossilized bones of large mammals. The existence of alluvial fan deposits in such high altitude (approximately 1400 m) expresses the intensity of the tectonic uplift in the area. The climatic conditions and especially the rainfall and wind have formed spectacular sculptured landforms that depict nature‘s strength, such as Eroded Conglomerates (Geosite 38, Figure 2). Mega Spilaio geosite is considered as one of the most important in the geopark area, due to the presence of the gorge’s local endemic Silene conglomeratica, found in small crevices in the conglomerates rocks Additionally, in this geosite the historical Mega Spilaio Monastery has been built, taking advantage of the very steep slopes that provided security from enemies and the natural cavities in one of which the monastery has been built.

Upstream, wide low-relief valleys with more alluviated channels can be found (segment C, Figure 3). The river head of Vouraikos River is located near Priolithos village.

4.1.2. Krathis River Area

The second most important river system of Chelmos Vouraikos UGGp is Krathis. The Krathis river watershed extends from Chelmos Mt to the south to Platanos Gulf west of Akrata to the north with an approximately N-S orientation (Figure 7). The river has a length of 42.9 km, and its watershed covers an area of 149 km² [51]. To the south the watershed is developed into Mesozoic limestones of the Tripolis zone which overlie metamorphic rocks of the Phyllite-Quartzite Series (Tessera Elata, Geosite 40) and are overthrusted by radiolarites, Cretaceous limestones and flysch deposits of the Pindos zone (Figure 1). The area is mountainous, surrounded by high peaks (highest elevation 2310 m), and steep limestone cliffs with high slope angles (Waters of Styx-Geosite 20, Balcony of Styx-Geosite 39, Figure 2). A well-developed karstic system can be identified in these extensive limestone rocks, with several springs, the most important of which is the spring of Waters of Styx (Geosite 20, Figure 2 and Figure 7) at 2100 m with high geomythological value. The impressive landscape with the very high and steep slope, the spring and the waterfall that are difficult to approach, have caused awe to people in the past. They attributed divine properties to the waterfall such as those described by the myth of Thetis and Achilles amongst others [52].

To the north, Pliocene and Quaternary rocks of clastic nature, mainly siltstones, claystones, sandstones and massive conglomerates, are the dominant formations. Four active main faults with almost E-W trends—Valimi fault, Akrata fault, Platanos fault and Vela fault that cut perpendicularly the north part of the basin of Krathis river [53,54,55] (Figure 7)—are related with the extension of the Corinth rift, causing the hinterland uplift and the deposition of these fluvial, alluvial, lacustrine and alluvial fan and delta fan deposits [49]. These faults are also responsible for the steep gorges and cliffs at slopes above 30°. Due to the significant uplift, the numerous faults in these rocks and the vertical erosion by streams and rivers make them unstable and prone to landsliding. At least 36 rotational landslides and rock falls have been observed across the Krathis watershed [56] (Figure 7 and Figure 8); the most important of these are the Valimi landslides (Figure 9) and the impressive Tsivlos lake landslide (Figure 10) (Geosites 32 and 19, respectively, Figure 2) which are placed at the northeast boundaries of Chelmos Vouraikos geopark along Krathis River watershed. These landslides are considered as major events that have intensely modified the landscapes, forming stunning geosites, and thus unique landforms that have been officially designated as geosites within the Geopark.

In the area of Valimi village (Geosite 32, Figure 2), there are two large, active rotational landslides (Figure 9), that present main landforms in the local landscape. Towards the south, Tsivlos Lake (Geosite 20, Figure 2) is located. It was formed from a massive landslide (Figure 10). According to [57] in 1913, a significant volume of rock debris collapsed from the footwall of the active Valimi fault in the Krathis riverbed. It moved downslope at a speed of 60 km/h, destroying the village of Sylivaina, impounding two lakes within the Krathis riverbed. Ten months after the catastrophic landslide, a massive flood event took place. The in-stream lake of Krathis River became overtopped, breaching the natural dam, which finally collapsed, causing the flood event, while the off-stream lake (Tsivlos Lake) remained unaffected and is still considered as being in an equilibrium state. Today, more than 100 years after the landslide event, there is an impressive mountain lake highlighting that even very recent geological processes can form breathtaking landscapes. Due to the young age of this lake, the riparian vegetation is in its infancy; however, the densely forested surrounding “compensates” visitors by providing a view simultaneously at Mediterranean coniferous forests of Pinus halepensis and at temperate mountainous coniferous forests of Pinus nigra and Abies cephalonica, since the altitude of the area is at the changing point of climatic zones. Four more landslides have been identified in the same area that were activated during the historical and prehistoric times [57] and which provide a unique characteristic of the Geopark’s landscape in the wider area of Tsivlos lake.

4.1.3. Kalavryta Basin

Kalavryta Basin is located in the central-western part of Chelmos—Vouraikos UGGp around Kalavryta city (Kalavryta tectonic graben geosite, Figure 2). Terrestrial and fluvio-lacustrine sediments cover most of the basin (Figure 1). It is a mountainous area where remnants of the old sedimentation history are exposed in several places. This area exhibits extraordinary cultural elements [22]. Local rural traditions and practices co-exist with natural environment, modern tourism activities and historical milestone elements of modern Greek history (e.g., Agia Lavra area—Geosite 8, Figure 2).

The oldest major north-dipping fault of the Corinth Gulf rift system is the Kalavryta Fault (Figure 2). Due to the lack of clear continuous surface exposures, the displacement of the Kalavryta block fault can only be estimated as 800 m [58] to 1200 m [13]. The sediments filling the half-graben basin that has been created after the Kalavryta fault was activated (Geosite 7, Figure 2) formed an alluvial fan system extending to the north until at least Kerpini. The alluvial fan is made of poorly sorted massive conglomerates where sand lenses are often present, attributed to channels existing at the surface of the alluvial fan. On a regional scale, fine-grained lacustrine successions at the lower stratigraphic levels can be found. These appear coarser in the south and progressively finer towards the north [13]. Coal facies within these sediments have been dated as Lower Pliocene (5.32–3.58 Ma) [59,60]. These coal facies currently represent the oldest dated level within the Kalavryta syn-rift sequence [61] and present rich macrofossil plants (e.g., Glyptostrobus europaeus, Quercus pseudocastanea, Liquidambar europaea; [62]) Open lignite mining has taken place in the area of Xidias (Geosite 9, Figure 2) and underground mining in the area of Palaeochori (Geosite 31, Figure 2). The lignite mining in the area has stopped because of, among other reasons, the high dipping angles of the lignite layers (caused by intense tectonics) which rendered the mines as economically unprofitable. Nowadays, limited remains of these old mines can be seen on the surface (buildings and machinery as well as some limited mining sites with mining rumble) and are used by the geopark as touristic sites.

During the Lower Pleistocene, WNW-ESE and NW-SE faults were formed in the area [63]. Within the Lower Pleistocene-Holocene period, as the active faults migrated northwards, the southern faults became inactive. The remaining flat area between the mountains, which is filled with sediments, has proved a suitable area for the development of a mountainous town, Kalavryta.

Nowadays, Kalavryta Basin is bordered to the south by the Kalavryta fault and a smaller WSW-ENE fault, which can be seen in the Agia Lavra area (Geosite 8, Figure 2), where another historic monastery exists. The northern limit of the Kalavryta Basin is bounded by WNW-ESE faults while towards the SE the Kalavryta graben is adjacent to the Kerpini half-graben [63] (Figure 2).

Kerpini half-graben has been formed by a similar process after the formation of the Kalavryta Graben. The strata of the Kerpini conglomerates are the lower fluvio-torrential conglomerate deposits in the Kalavryta Basin. They occur locally, over the alpine substratum, and outcrop at the northern margin of the basin, in normal contact below the Kalavryta fluvio-torrential sediments. Since Kerpini conglomerates are stratigraphically found above the lacustrine deposits of Kalavryta Basin, it is estimated that they were deposited during the Early Middle Pliocene [19]. Kerpini conglomerates (Geosite 5, Figure 2) are exposed in several meters of high steep slopes and form magnificent landforms as wind and water sculpts their surface through time (Figure 6).

Area South of Kalavryta

The mountainous landscape southeast of the town of Kalavryta (Figure 2), develops within medium-to-thick platted gray Cretaceous limestone of the Tripolis Zone (Figure 1). They present typical surface karst formations covered by rich vegetation. This forested part of the Natura 2000 Network, characterized as an Aesthetic Forest, is of significant importance since it provides invaluable ecosystem services to the town of Kalavryta, such as protection from mass flows and landslides. The landscape presents small-scale dissolution sculpturing phenomena because of rainwater, like small surface pits that are covered by soil (e.g., in Valvousi-Geosite 26, Figure 2). The tops of the limestone blocks are rounded, which denotes dissolution of limestone under soil horizons. Moreover, solution flutes can be found. In the middle scale, limestone pavements (with clints and grikes) can be found scattered around the area. The surface karstic geomorphological features that are observed in this area are connected to the other middle or large-scale karstic features that can be found in the geoparks’ area, like the karstic Cave of the Lakes (Geosite 11) and the karstic spring in Keramidaki (Geosite 27, Figure 2).

Area East of Kalavryta

Kalavryta Castle of Orias (Geosite 42, Figure 2) is located at the eastern boundaries of Kalavryta city, on a nearby hill. It towers approximately 400 m higher than the town, at an altitude of about 1170 m. This historical castle was built on Upper Triassic–Upper Eocene thick-bedded limestones and dolomites of the Tripolis zone that emerge from the surrounding sediments and provide a natural castle-like setting. Modern screes and talus cones have been deposited around the hill. Screes consist of clastic sediments due to the erosion of the surrounding outcrops. Talus cones are located at the foot of the hill and derived from the limestones and dolomites. Around the screes, the Oria Formation is found, which consists of siltstones with clay and sand intercalations [19]. The rocks of this formation are of Middle Pleistocene age and have terrestrial, fluvial and lacustrine origin.

4.1.4. Loussoi Karstic System

Loussoi valley and the neighboring limestone highlands compose a very well-developed karstic system that exhibits a high number of characteristic karstic geomorphs such as a polje, hums, sinkholes, springs, caves, etc. (Figure 11). Loussoi polje (Geosite 23, Figure 2) is elongated towards the SSW-NNE blind valley, located 12 km SW from Kalavryta, which occupies a surface area of 13.2 km² (Figure 12). It is situated in a mountainous area at an altitude of 940 to 1100 m a.s.l. surrounded by limestone mountains. The valley is drained by the small river Mana [64]. According to historical sources, Mana River flowed towards the north, to Kalavryta city, but was dammed due to a large landslide north of Ano Loussoi village during a glacial phase. As a result, the valley turned into a lake. The flat surface in combination with the water availability and the fertile sediments have led to the settlement of people in the area since the antiquity, as implied by the ruins of the ancient Temple of Artemis. The area is heavily cultivated until today.

Most of the polje’s area is covered by Late Pleistocene to Holocene alluvial deposits while about 35% is covered by karstified carbonate formations [64], mostly severely tectonized (faulted and folded) Cretaceous limestones of the Pindos zone. Their tectonic deformation in combination with the alternations with flysch and radiolarites allows the appearance of 23 mostly seasonal contact springs in the area (Figure 11). At the northeastern part of the polje area, a SE-NW oriented normal fault brings the Pindos zone limestones in contact with limestones of the Tripolis zone (Figure 1). The karstic system of these limestones is more extended and well developed due to their greater thickness and the lower tectonism. As a result, the spectacular fault-overflow springs in Planitero area have been developed (4 m²/s of water deriving from Mt Chelmos) (Geosite 14, Figure 2 and Figure 11) [65]. The springs at Planitero area are the springs of Aroanios River, where the most extensive floodplain forest of the geopark area dominated by Platanus orientalis galleries, is located. The place had been recorded by the ancient historian and traveler Pausanias.

Except for the Mana River and the springs, the area is drained through two pairs of sinkholes lying at the ENE part of the polje area, the bigger one of which is the Loussoi solution sinkhole (Geosite 13, Figure 2 and Figure 11). Close to the sinkholes area, a spectacular pothole-cave named “Kaliakoudotripa” (360 m²) exists. It has been explored since the 1970s, but it has not been touristically exploited despite its beauty [66]. Finally, in the area of the polje, at least six hums can be noticed (Figure 11) [67].

In the surrounding area some important karstic geomorphological features can also be found. East of the polje, near Kastria village, the popular Cave of the Lakes (Geosite 11, Figure 2 and Figure 13) is the most emblematic geomorphological feature of the entire area. The cave develops in the limestones of the mountain Amolinitsa along a fault line oriented NW-SE which also reaches the Planitero area. Its first part develops in the Cretaceous limestones of Tripolis Zone and a second part in the Upper Cretaceous limestones of Pindos Zone. The basic geometry of the cave, with a relatively small width and a large roof height, is determined by the fault while its final geometry is determined by secondary joints. The cave is 1950 m long, and its elevation is 85 m a.s.l., covering an area of 20,000 m². Apart from the rich and impressive speleothems in part of the cave, the most impressive feature is the presence of 13 underground lakes located at different levels that were formed due to the slow flow and water stagnation, resulting in the creation of calcitic walls (gours or rimstones) which continue to grow until today. The Cave of the Lakes geosite has been used by people in antiquity as a place of worship and several myths are related to it.

The large fault that brings in contact the two geotectonic zones in the area of Kastria also creates several other interesting geomorphological features such as the waterfall of Mavri Limna (Geosite 12, Figure 2) in radiolarites and the waterfall in the gorge of Analipsi Byzantine chapel area which develops in Tripolis limestones (Geosite 25, Figure 2). In Analipsi chapel area a small cave decorated with speleothems can also be seen and constitutes the church’s sanctuary (Figure 11). Moreover, in the area east of Kastria, a system of alluvial fans creates a special clastic formation which can easily be noticed east from the entrance of the Cave of the Lakes and also behind Analipsi chapel.

4.1.5. Mt Chelmos

Mt Chelmos (Figure 2) dominates the central part of the geopark’s geomorphology, with its imposing limestone rock volume with steep rock cliffs (Figure 14). The altitude of its highest peak (Psili Korfi, Geosite 34) is 2355 m a.s.l. Several other high peaks (e.g., Neraidoraxi—2340 m a.s.l., Avgo—2138 m a.s.l., Profitis Ilias—2282 m a.s.l., Kaki Raxi—2000 m a.s.l., Figure 2) synthesize a relatively complex geomorphology which hosts many characteristic landforms and habitat types (e.g., rich in endemic species, oromediterranean grasslands, screes and rocky slopes with chasmophytic vegetation).

Mt Chelmos is composed of limestones of Tripolis zone tectonically overlaid by limestones, radiolarites and flysch of Pindos zone (Figure 1). The lower stratigraphic unit that can be seen at the lower-altitude slopes of northeastern Chelmos is the volcano-sedimentary Tyros Sequence and the metamorphic rocks of the Phyllites-Quartzites Series. Because of the intense tectonic movements during the Alpine orogenesis these rocks appear severely folded and faulted. The high altitude of Mt Chelmos peaks reflects the high uplift rates of Northern Peloponnesus as a whole during the Pleistocene and Holocene [48,68,69,70,71,72].

Mt Chelmos displays several landforms characteristic of extensive past glaciation in the form of glacial valleys, moraines and cirques, glacio-fluvial fans, etc. (Figure 15). At least three glacial phases can be identified by the different landforms on the flanks of Mt Chelmos [20]. These were dated as Middle to Late Pleistocene. The remnants of the past glaciation phases are distributed radially around the highest peaks of Chelmos (Psili Korfi and Neraidoraxi); in these locations, patches of varying size assigned to the priority habitat for conservation in EU “Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas, in Continental Europe)” are recorded.

The most important features are located in Spanolakkos (Geosite 30, Figure 2) and Xerocambos (Geosite 21, Figure 2) areas at the northwestern flanks of Mt. Chelmos. In Spanolakkos valley, characteristic glaciofluvial sediments can be seen scattered over wide areas (Figure 16). At the middle part of the valley a characteristic arcuate moraine ridge and a characteristic incised valley can be seen (Figure 17) while the southeastern limit of the past glacier is marked by a cirque.

In Xerocambos valley, parts of the glacial landforms have been partially destroyed by the construction works of the Kalavryta Ski center. Additionally, the glacial valley and the moraines in this area have been reshaped and are used nowadays as ski slopes. The southern upper limit of the past glacier is also marked by a cirque, while a moraine is clearly seen further to the north. Scattered subrounded boulders are present throughout the lower part of the valley, where numerous endemic and range-restricted species occur (e.g., habitat of the Peloponnesian endemic and EU priority species for conservation Globularia stygia, as well as of the near-threatened endemic Gymnospermium peloponnesiacum. The high altitude and the flat topography of the Xerocambos area served as a suitable location for troop development, supply and battle (Chelmos battle) during the Second World War.

The largest glacial valley of the area is the one that drains the northeastern flanks of Mt Chelmos (Neraidorachi valley) (Figure 15). It is claimed to have been formed during the oldest and most extensive glaciation phase when a single ice sheet was covering the entire area. A cirque (Epano Kambos cirque) marks its southeastern valley north of Psili Korfi (Figure 18) (Geosite 34, Figure 2). Glaciofluvial sediments can be seen throughout the area (although covered by vegetation in most parts). Several moraines exist on the sides of the valley. Since Mt Chelmos mostly consists of carbonate sediments, karstic geomorphs are often created. A characteristic sinkhole has been recorded in the area of Epano Kambos (Geosite 34, Figure 2). Moreover, in the upper valley the spectacular Styx spring and waterfall (named after an ancient Greek river known from mythology) (Geosite 20, Figure 2) is developing as an over-steepened U-shaped valley. This area is the habitat of the valley’s local endemics Alchemilla aroanica, Hieracium greuteri, Lonicera alpigena subsp. hellenica and Polygala subuniflora, Valeriana crinii subsp. crinii, as well as of the EU priority for conservation species Globularίa stygia and Viola delphinantha.

The 200 m a.s.l.-high waterfall forms a unique, breathtaking landform formed by the Mavroneri River, which is a tributary of Krathis River. Further to the south, at the center of the upper valley, is the Mavrolimni seasonal glacial lake (Figure 19), where rare, endemic plant species are recorded (e.g., Aquilegia ottonis subsp. ottonis, Achillea umbellata, Dianthus tymphresteus, Saxifraga sibthorpii). Glacial lakes are claimed to have been formed in other areas of the mountain ridge. In the Kato Kampos site, the existence of a palaeolake (which is now a marshland at the center of a cirque basin) is indicated by a palaeoshoreline, while in the Xerocambos area a terminal moraine has been claimed by [73] to block the valley, forming a seasonal lake. On Neraidorachi plateau, ice-molded bedrock (knolls) implies the presence of glaciers (northeast of Psili Korfi and east of Mavrolimni).

Two other glacial valleys drain the southern and southeastern flanks of Mt Chelmos. In Laghada valley, glacial features are found as poorly preserved glaciofluvial sediments in the Strogilolaka area. In the Kato Kampos area, a very representative glacio-karst cirque basin has been preserved. Chaliki incised valley drains the southern flank of Mt Chelmos (south of the steep rocks of Psili Korfi). The upper valley contains eroded moraines. The lower valley forms a characteristic braided river system forming alluvial terraces near Planitero village.

4.1.6. Feneos Valley

Feneos polje is located at the southeastern part of the geopark and occupies an area of approximately 42.6 km² (Figure 20). It is an extended flat-floored depression which nowadays is intensely cultivated. It constitutes an eminent geomorphological feature (Figure 21) with several secondary geomorphological elements such as palaeolakes, juvenile rivers, sinkholes, etc. that lie in between high mountain peaks.

Feneos polje constitutes the floor of the Feneos valley (700—2100 m a.s.l), which was formed during the Middle Pleistocene as a result of complex lithological-hydrogeological structure [74] and the high tectonic uplift of Northern Peloponnesus. The basement of the valley consists of Pre-Neogene sediments (limestones). Olvios River runs through the elongated valley, filling it with Pliocene and Pleistocene sediments (conglomerates, marls, sandy marls and sandstones). The cohesive conglomerates that are found in the north of Feneos valley slow down the erosion rate. The high uplift rates of the Northern Peloponnesian coast exceeded the Olvios River’s ability to erode vertically upstream during the Upper Pleistocene. As a result, the initial course of the river has changed and a reversal flow has been produced to the south, forming an internal closed drainage basin, the Feneos valley. This basin, because of the limestone basement, has evolved in a closed karstic surface landform, the Feneos polje. The surface drainage is captured by three solution sinkholes (Geosite 22, Figure 2) created through suffusion processes and lying in the southern part of the polje at the foot of Mt. Saitas. The sinkholes are a few meters wide and are connected with ancient Greek mythology and more specifically with Hercules, who was supposed to unblock them so that the polje would be drained and used for cultivation again. This pinpoints their diachronic importance for the landscape and their connection to the local community. In the past, these sinkholes have been blocked by debris carried by streams. As a result, swamps were created which evolved in a lake system (Feneos palaeolake). The palaeolake reached 194 acres and 40 m depth [75] at its greatest extent. Due to the surrounding mountains, the lake was only fed by hillside runoff and underground springs [76,77]. This palaeolake has left its marks on the landscape as palaeoshorelines. No such lake can be seen in the area in modern times. The water from the sinkholes through the underground drainage system reaches the headwater springs of the River Ladon (Geosite 15, Figure 2), a tributary of the River Alpheus, near Likouria village.

Feneos valley is bordered to the west by high limestone peaks. Ntourntouvana peak (2060 m a.s.l.) (Geosite 35, Figure 2) is composed of Upper Cretaceous–Eocene limestones of Tripolis zone, where rudists have been found among other fossil fauna [78]. Further to the northwest another high peak, Madero (2143 m a.s.l., Geosite 37), dominates the landscape. At Madero Limestones of Olonos-Pindos Zone are overthrust on limestones of the Tripolis Zone.

The landscape of the Feneos valley has been severely affected by anthropogenic activities and can be considered as a site of high cultural value [22]. In addition to the systematic cultivation of beans in the area, a dam was also built during the mid-1990s (Figure 20). The dam drains the water of Doxa stream, which is a tributary of Olvios River. The dam has a length of 225 m and it was built in order to cover the irrigation needs of Feneos valley and to prevent flooding events. Due to the dam’s existence, an artificial lake of outstanding beauty has been formed. Lake Doxa lies at 900 m a.s.l. and covers 480 acres. It hosts 5 million m² and is a deep artificial lake (40 m depth) relative to its extent. Because the irrigation network of the area has not been constructed yet, its water level fluctuates only due to natural conditions, and therefore species-rich and abundant aquatic vegetation has developed to such an extent that lake Feneos resembles ecologically a natural lake. Black pine (Pinus nigra) forests mixed with Greek fir (Abies cephalonica) complete the landscape canvas. It is one of the most striking examples of when human intervention in the natural landscape has a positive effect. At the flanks of Lake Doxa, the tectonic window of Feneos is found, where the Phyllite–Quartzite series of rocks crop out below the two tectonic units of the Hellenic nappe stack, the Pindos and Tripolis nappes [10]. Between Ntourntouvana and Doxa lake a large pothole, Feneos pothole, one of the largest cave systems of the Geopark, is located with a total depth that exceeds 130 m.

4.1.7. South Part of the Geopark

The Southern part of the Geopark’s area (south of Kleitoria) is—from a geological point of view—characteristic of Pindos zone formations. These are deep water carbonates (limestones), siliciclastic and siliceous rocks (flysch and radiolarites) ranging in age from Late Triassic (including the local Priolithos formation) to Eocene (Figure 1). Intense thrusting resulted in regular in-sequence thrusting so that the respective lithologies are preserved as a series of thrust sheets [7]. The intensively tectonized lithology of the area causes an increased fractionation, which results in higher erosional rates. Accordingly, the landscape of this area is smoother, and steep slopes are lacking (Figure 20). The existing mountain peaks (Agia Triada, Profitis Ilias, Afrodisio, Ai Lias and Ai Thanasis, Figure 2) slope gently, creating a characteristic landscape. The southern margin of the Geopark is determined by the meandering riverbed of Ladon, a tributary of Alfeios. It was named after the mythological river deity Ladon, one of the sons of Oceanus and Tethys. Ladon rises partly from Ntourntouvana and partly from Kefalovryso. It flows for more than 60 km. A special geomorphological feature of the area is the headwater of Ladon river SW from Likouria village and at 469 m a.s.l. altitude. It is called the “Eye of Ladon River” because of its special circular morphology (Geosite 15, Figure 2) The water gushes from a single sinkhole with great speed and forms a small but deep karstic lake (Figure 22). The karstic conduit underneath the lake descends with inclination 10–15° for approximately 120 m and ends up in another karstic conduit which develops upwards with a square shape. The maximum depth is 47 m. The surrounding area, accessible to visitors, is characterized by riparian vegetation, dominated by large stands of Typha sp. and well-developed galleries of Platanus orientalis.

5. Discussion

While a precise, universally comparable count of exclusively geomorphological sites is often challenging to ascertain across all the geopark—as many report composite geosites encompassing geological, paleontological, and tectonic significance alongside geomorphological features—their prominence is undeniable. For instance, the Burren and Cliffs of Moher UNESCO Global Geopark in Ireland showcases exceptional karst landscapes, including the iconic limestone pavements and the dramatic Cliffs of Moher, representing a significant portion of its reported nine key geosites (Burren Ecotourism Network, n.d.). Similarly, the Vikos-Aoos UNESCO Global Geopark in Greece stands out for its extraordinary erosional and tectonic geomorphology, epitomized by the Vikos Gorge, one of the deepest gorges globally in terms of proportions. Another characteristic example is Río Lobos Natural Park, located in Castilla-León. It is a protected area notable for its combination of natural and cultural heritage. Its geomorphological importance is reflected in the identification of 14 geomorphological sites which are recognized for their scientific, educational, and tourism potential [2]

Within Chelmos Vouraikos UGGp, nearly half of the designated geosites (21 out of 43) have been characterized as primarily or secondarily of geomorphological interest (Table 1). Moreover, as proved in this work, many more geosites have geomorphological features and these seem to affect both their floristic elements and their cultural characteristics (e.g., Ladon springs, Feneos sinkholes, Cave of the Lakes, Loussoi polje and Niamata geosites, which are not listed as geomorphological sites but still present important geomorphological characteristics). This fact denotes the importance of geomorphology as a driving factor for both natural and cultural evolution of the area.

As far as the ecological aspect is concerned, it is worth noting that out of the 19 geosites of Chelmos Vouraikos UGGp listed in [5] as geomorphological (Table 1), 11 bear a high score (>5) to criterion 2 (ecological and protection) with Kerpini conglomerates and Waters of Styx and Psili Korfi geomorphological sites achieving almost top scores. However, it is often challenging to directly correlate individual geosites with the local plant communities, as several geosites represent point-specific features, whereas vegetation typically extends over much broader spatial scales. A characteristic example would be the Water of Styx geosite. The actual site is the spring and the resulting waterfall on which no plants are growing. In the immediate vicinity of the actual site there are plenty of very important endemic species which must be taken into account, since they may be related to the existence of the spring and waterfall (water availability).

The cultural aspect of the geomorphological sites has been evaluated under criterion 3 (cultural). It is worth noting that almost all geomorphological sites present low scores (<5) in this criterion, with the only exception being Mega Spilaio geosite (score 5.9). Nevertheless, this study presented important examples of very strong cultural elements driven by geomorphology. This implies that the cultural criterion as calculated by [38] gives a general idea of the cultural value of the geosites but fails to recognize deeper relations of special geological characteristics with culture. For instance, Xerocambos breccia geosite’s geomorphological features strongly impacted its cultural characteristics, even if its cultural criterion score is very low (1). Moreover, there are geosites whose geomorphological features strongly impact their cultural characteristics, and additionally these cultural characteristics are very important for a specific subcriterion only. As an example, we mention the Water of Styx geosite, whose geomorphology has a very strong impact on mythology and its mythological value is very high. The same does not apply to other sub-criteria of the cultural criterion. As a result, the total cultural criterion score is low (3.3). The cultural criterion is taken into account also for the calculation of Vedu (educational value) index. The values of this index for the geomorphological sites are higher than the cultural criterion alone (from 2.1 in Chelonospilia geosite to 6.8 in Mega Spilaio geosite), but they still remain low. This does not mean that the educational value of certain geomorphological sites is low, but rather the low cultural score influences the values of the index. For example, the Vedu of the Waters of Styx geosite is 6 (which is a moderate value) even if the interest of people for geomythology is considered extremely high. These considerations prove that the connection between geomorphology and culture is strong but cannot be estimated taking into account only the measured indices. A deeper and specialized study of each case is needed.

The Vtour index calculated in Golfinopoulos et al., 2022 [5], provides data for the geotouristic value of the geomorphological sites. Accordingly, the Vtour index for these geosites exhibits diverse values (from 2.1 for the Eroded conglomerates geosite to 7.8 for the Kalavryta tectonic graben geosite). Only four geomorphological sites bear values more than five, which means that according to this index the geomorphological sites have medium to low touristic value. This might be the case because many of them may have good scientific and/or educational value, but moderate visual appeal, accessibility, infrastructure, or visitor readiness. It is interesting enough to attract tourists, but not enough to be considered of high value without further development or promotion. Moreover, some of the most emblematic geosites of the area with prominent geomorphological characteristics bear a high geotouristic value according to [5] (Cave of the Lakes and Portes-Triklia, Vtour = 6.7).

While the area has gained recognition and protection as a National Park since 2009 for its notable biodiversity, it is the striking geomorphological features that most effectively draw tourists’ interest. For instance, Styx spring and waterfall (geosite 20) shows a high number of important plant species, but it is best known for its geomythological value. A similar example would be Cozia National Park in south-central Romania, which was primarily designated as a protected area for its rare and endemic plant species. However, in practice, it is the park’s remarkable geomorphological features such as the Doabra Snails, Ţurţudanu Peak, Lotrişor and Gardului Falls, Stone Gate, Beţel Falls, the taffoni formations in the Doabra and Glodului Valleys (locally known as the “Rock with Holes”), Teofil Tower, and the Olt Gorge that attract most visitors [79]. The high visibility of geomorphological sites with ecological value can contribute to raising environmental awareness and, consequently, to the protection of biodiversity.

The substantial number of identified geomorphological sites within the Geopark underscores its profound commitment to recognizing geomorphology as a distinct scientific discipline, simultaneously establishing the area as a highly significant geomorphological destination.

6. Conclusions

The review of the geomorphological features of Chelmos Vouraikos UGGp and the discussion of the available data highlight several overarching conclusions that clarify the geomorphological, ecological, cultural, and geotouristic importance of the geosites within Chelmos Vouraikos UGGp:

• Geomorphology is a dominant component of the geopark, with nearly half of its geosites exhibiting primary or secondary geomorphological significance, reinforcing the area’s status as an important geomorphological destination.
• Many geosites not officially classified as geomorphological sites still display strong geomorphological controls, influencing their floristic characteristics and cultural development. This highlights geomorphology as a key driver shaping both natural and cultural evolution in the geopark.
• Ecological importance is closely linked to geomorphology, with more than half of the geomorphological geosites receiving high scores for ecological and protection criteria, demonstrating the strong interplay between landforms and biodiversity.
• Cultural values associated with geomorphological sites are underrepresented by existing assessment indices, as these metrics often fail to capture deeper or site-specific geo-cultural relationships. Examples such as Xerocambos breccia and Waters of Styx geosites, show that unique cultural significance rooted in geomorphology is not adequately reflected in aggregated scores.
• Educational (Vedu) values of geomorphological sites remain moderate mainly due to the influence of low cultural scores, rather than limited educational potential. Several geosites possess significant geocultural or geomythological interest that is not fully captured by standardized indices.
• Geotouristic value (Vtour) scores for geomorphological sites range from low to medium, primarily due to factors such as moderate visual appeal, accessibility, infrastructure, or visitor readiness. Only a few geomorphological sites surpass a high geotouristic threshold, though emblematic sites like Cave of the Lakes and Portes-Triklia perform well.
• Geomorphological features are among the primary drivers of tourist interest, often outweighing ecological values, as seen in Chelmos Vouraikos UGGp.
• The high visibility and appeal of geomorphological sites contribute significantly to environmental awareness, encouraging conservation of both geological and ecological heritage.
• Overall, the large number and diversity of geomorphological sites reflect the Geopark’s strong commitment to geoscience, underscoring its importance as a region with outstanding geomorphological heritage, scientific value, and geotourism potential.

Chelmos Vouraikos UGGp is one of the greatest examples of a unique combination of different landforms and landscapes all in a single unified area protected for its geoheritage. It can serve as an educational tool for the interchange between geological processes and landscape evolution. Moreover, through this work the connection between geological background, landscape and vegetation cover is clearly shown. In the area of the Geopark the geological processes have created magnificent landforms such as high mountain peaks, deep gorges, glacial and karstic landforms. The popularity of these geosites can help strengthen people’s awareness regarding the conservation of the geological monuments. Moreover, through research and establishment of new geosites, people will have the opportunity to better understand the geological processes that form the earth’s surface while admiring the picturesque landscapes of the geopark’s area.