E. Speleopark 

Beyond the visible geosites of Psiloritis, there are those that can only be discovered by following the hidden, underground path of water through the carbonate rocks. These are the unique formations created by karstic dissolution: the caves

The dominance of carbonate rocks in Psiloritis, combined with their alternation with impermeable rocks and the mountain’s complex geological history, has resulted in the formation of countless caves. From surface sinkholes and vertical shafts to caves of varying size and shape, these underground voids are the missing rivers of Psiloritis.

Life has adapted to these subterranean spaces, creating species that thrive in eternal darkness just as their ancestors do on the surface. Besides several bat species, snails, spiders, pseudoscorpions, isopods, and insects form the main groups of cave fauna.
Caves are also deeply connected to human presence on Psiloritis. Since the earliest human occupation of Crete, they have served as places of worship, dwellings, dairies and cheese-storage facilities, refuges in difficult times, and sites of sacrifice. For this reason, most caves hold significant archaeological and historical value (and, as in all of Greece, are considered potential archaeological sites).

Many caves are of exceptional beauty, important ecosystems, and key elements in the circulation of underground water. Some are easily accessible and open to visitors, such as the developed caves of Sfentoni at Zoniana and Gerontospilios at Melidoni. Others, however, challenge even the experts, such as Chonos at Sarhos or Tafkoura at Petradolakia

The most important caves of Psiloritis could constitute a separate “sub-park”—the Speleopark—suitable for educational, sports, scientific, and touristic activities. Although only a few of these caves are under official management, most can be accessed, making visitors responsible for protecting this unique natural wealth and the fragile life it hosts.

E1. Sfentoni’s Cave (Sfentoni’s Hole) 

Sfentoni’s Cave lies at the entrance of the village of Zoniana, in a privileged position overlooking the Mylopotamos Valley. It is one of the two “developed” caves of Psiloritis, fully accessible (including for people with disabilities) and among the most beautiful and important caves in Greece, due to its rich decoration.

The cave develops within limestones of the Tripolis unit, a few dozen metres above their contact with the Phyllite–Quartzite series.

A major fault shaping the slope played a decisive role in its formation: water followed the fault, creating a long, narrow cave with a total area of about 3,000 m². Visitors can explore two-thirds of its extent along a 270-metre pathway.
Inside, four species of bats and dozens of invertebrates (molluscs, spiders, pseudoscorpions, isopods, millipedes, springtails, orthopterans, etc.) have been recorded, some of which are colourless and blind, while at least two are endemic to Sfentoni’s Cave. The cave also has archaeological value:

excavations revealed its intermittent use by shepherds for thousands of years. Pottery dating has revealed a continuous, though limited, use of the cave from the Neolithic period to the present.

E2. Kamares Cave 

Kamares Cave is one of the highest-altitude caves in Crete. It lies on the southern slopes of Psiloritis, just below Mavri Korfi (Black Peak). The cave consists of a large central chamber and develops within dolomitic limestone of the “Tripolis” unit, directly above the Cretan Detachment Fault.

Access to the cave is possible only via mountain trails from either the village of Kamares or the Nida Plateau.
Kamares Cave holds exceptional archaeological importance, as the Minoan pottery discovered within gave its name to an entire style of ceramic art. These Early Minoan vessels (ca. 2000 BCE) are masterpieces of craftsmanship, featuring thin walls, polychrome decoration, and intricate designs.

During this period, the cave—likely due to its commanding view over southern Crete—was established as a sacred site. Archaeological evidence also indicates sporadic use since the Neolithic period.

E3. Gerontospilios Cave 

On the northern slope towering above the village of Melidoni, within the Plattenkalk limestones, lies Gerontospilios Cave. Visitors can only admire the first chamber—which is nonetheless quite impressive—since the deeper sections remain closed due to ongoing archaeological excavations.

Even this limited access is enough to captivate the visitor. The main chamber is one of the largest in Crete, with enormous stalactites and stalagmites. Sadly, a significant number were destroyed by vandalism in the distant past.

The cave has been in use since the Neolithic period. During the Minoan and Classical eras, it was dedicated to the mythical bronze giant Talos, protector of Crete, and to the god Hermes. Above all, however, Gerontospilios is a place of sacrifice: during the Ottoman period, hundreds of women and children perished here in a horrific massacre.

E4. Chainospilios Cave 

Outside the village of Kamaráki lies Chainospilios, a long, gallery-shaped cave that forms part of an ancient underground riverbed. The cave is still active in most of its sections. It extends for approximately 200 metres, while a parallel gallery of 120 metres features rich speleothem decoration. The cave has developed within Miocene brecciated limestones (12 million years old) that overlie the region’s ophiolitic rocks.

Its narrow and sloping entrance makes access difficult for those unfamiliar with caving. However, the impressive interior decor rewards the effort. Massive stalagmitic columns over 6 metres high, along with numerous smaller and larger stalagmites, adorn the cave. Traces of erosion by the ancient river's water are visible along nearly the entire ceiling of the cave.

E5. Tafkoura Pothole

One of the many potholes in the Petradolakia area and among the most important in Greece is Tafkoura. It is the second-deepest cave pothole in Crete (–860 metres below the surface) and one of the deepest in the Balkans. The cave has developed exclusively within the Plattenkalk marbles of Psiloritis, and its formation likely began along one of the many faults cutting through the area's rocks. Water followed the uplift movements of the Psiloritis massif
progressively carving deeper into the rock en route to the sea, eventually forming this vertical cave system. With a total mapped length of 6.5 kilometres, Tafkoura is the longest cave in Crete. Together with Tafkos at Petradolakia (–475 m), Diplotafki (–400 m), and Mythia Kampathoura (–270 m), it constitutes one of the deepest karst conduits of Psiloritis, which channel rainwater to the karst spring of Almyros, located a few kilometres west of Heraklion.

E6. Mougri Cave 

Mougri Cave lies in the heart of Kouloukonas, northwest of Vosakos Monastery. It develops within the lower layers of the local Plattenkalk limestone group, along one of the many faults that have affected the region
The cave is particularly impressive due to its rich speleothem formations, mainly along its walls. It includes two main chambers, with a total surface area of approximately 2,000 m². In the past, it was more active, as indicated by large calcite basins for water collection found in its deeper parts. The cave has been used by humans since at least the Minoan period. Access is limited to trained speleologists.

E7. Doxa Cave 

Doxa Cave is a small cave that has formed within the Tripolis limestones, exactly where they come into contact with the Phyllite-Quartzite rocks of the Marathos area. Despite its limited size, the cave features beautiful speleothems in various colors and shapes. Due to its proximity to the provincial road network, access to the cave is relatively easy.

E8. Trapeza of Tylissos 

The Trapeza cave has developed within the limestones of the Tripolis Unit that form the mountains of Tylissos. A relatively small entrance leads to a 30-meter-long chamber covering about half a stremma, surrounded by smaller side chambers. At the entrance of the main hall stand two massive columns. From an archaeological perspective, this is the most important cave in the wider Tylissos area, as it served as a place of worship
from the Middle Minoan to the Late Minoan period.

E9. Kalo Chorafi

Kalo Chorafi is a coastal cave in the Bali area, formed within the Platy Limestones. The cave is small in size and lacks significant speleothem decoration. Many of its parts have been damaged by sea erosion.

However, several decades ago, the German paleontologist Siegfried Kuss excavated numerous bones of deer, dwarf elephants, and rodents from the cave floor. These remains date to the end of the Pleistocene epoch (about 150,000 years ago). Kuss's findings shed light on life in Crete during the last glacial periods.

E10. Chonos of Sarchos

Chonos Cave, located in the Sarchos area, is a favorite among speleologists due to its complexity and considerable length. The cave functions essentially as a siphon and a temporary spring, as its deeper sections flood rapidly during periods of heavy rainfall—making it quite dangerous. In fact, during extended periods of intense rain, the entire cave can flood and water gushes out of its entrance.
its

With a mapped length of nearly 1,500 meters and a depth of 225 meters, the Sarchos cave is one of the main conduits feeding the Almyros spring, located just 13.5 km from Sarchos. It is believed that the cave is connected through siphons and sinkholes to the Livadia plateau of Krousonas and extends northwards along the major fault zone of Krousonas–Tylissos. It has developed within Tripolis limestones, which at a depth of 100 meters are dolomitized and heavily faulted.

Chonos is also a historic cave, as it was used several times by the villagers as a refuge during the Cretan uprisings under Ottoman rule.