The composition of Kalymnos' rocks has contributed to the creation of numerous caves. Many of those present, apart from geological interest archaeological interest as well, as they were inhabited in the past or were used as places of worship.

Sixteen caves are accessible, while three of them, the Kefalas cave, the Epta Parthenon (Seven Virgins) cave and the Skalia cave are the ones that deserve to prioritize.

Kefalas Cave

In Kefalas cave you will be impressed by the imposing, 103 meters long, hallway with the huge stalactites and stalagmites. You will also be able to see traces of the worship of Zeus, which is the reason why the cave bears the alternative name 'Cave of Zeus'.

It is located near Pothia, beyond the Monastery of St. Catherine in Kefalas area. You can go there by boat or along the provincial paved road from Pothia (note that this road later on becomes a dirt road). Once you reach the top of the hill where the road ends, and after you have passed in front of St. Catherine's Monastery, will need to follow the blue signs marked on the rocks in order to reach the cave.

The cave is open to the public daily, from 08:30 to 14:00, except from Tuesday and Thursday. The guardian in the entrance of the cave will provide you with a helmet that bears integrated light. However, it is advised that you visit the cave equiped with your own torch in order to gain better sight.

Epta Parthenon (Seven Virgins) Cave

The Epta Parthenon (Seven Virgins) cave is located in the region Flaskas. It was named after the legendary seven virgins who hid into the cave in an attempt to escape from a pirate attack, but they never returned back to their castle. Various offerings and archaeological findings have been discovered within the cave, while inside there is also a small lake with stone-carved stairs.

Skalia Cave

The Skalia cave - or St. John's cave - is located in Massouri, at about one kilometer distance from Skalia. It includes natural stalactites in strange formations and is considered relatively steep, so you should be quite careful when visiting. Its impressive decor will leave you mesmerized nonetheless.

Stimenia Cave

The Stimenia cave is in the northeast side of Vathys Valley, in St. Nicholas region. Not too far from there, in the northwest side of the valley, there are two more caves, the findings of which indicate their residential use in the distant past.

The Stimenia cave has a hole on its top that serves as a means of both illumination and entrance for the people, while its interior decor is very impressive. Early christian and byzantine pottery, ancient stone buildings and ruins are found scattered around the cave.

Choiromantres Cave

Choiromantres Cave is located on the south slope of Pothia, below the monastery of Agioi Pantes (All Saints). Neolithic findings and shells which date up to the early Christian era were discovered within and around the cave. Their presence testifies to the continuous habitation and the ritual use of site. Unfortunately, the form of the cave was altered after the collapse of the dome.

Agia Varvara Cave

The Agia Varvara cave took its name from the church situated nearby, on the hill of Troutsoulas. It consists of two main chambers that communicate through a narrow passageway. The rare findings discovered in the cave indicate its use since the Early Bronze Age.

Daskalio Cave

For the more experienced explorers we recommend the -relatively inaccessible- Daskalio cave in Vathys, which you will access after taking off some carved steps. The prehistoric findings, the neolithic tools and the late minoan-age pottery found in there reveal human presence in the region since ancient times, demonstrating at the same time the use of the cave for both habitation and worship.