Karavomylos in Kefalonia is a picturesque settlement by the sea with 389 inhabitants and intense geological phenomena in its wider area. On the south side of the village, about 250m from the sea and at an altitude of 15m. is the land cave of Zervati, also known as the “Blue Cave”. It is essentially a vertical cave that is part of the wider karst network of the Sami region. In addition to its geological value, the cave is of particular ecological interest, since the two lakes of the cave are home to rare aquatic plants, sea bass and eels.
The cave has a Northwest – Southeast direction with its total length, including the flooded rooms reaching 235m. and its average width is 30m. The cave entrance has a 50 X 30m. dimension, and it was created by the precipitation of the roof of the pre-existing closed room. The result is the creation of a ridged cone (dome) over 10m high., which is located in the centre of the open part of the cave and is its highest point.
On either side of the debris dome (NW and SE) there are two lakes with brackish water above which the roof is maintained and a strong presence of stalactites is observed on it and on the cave walls.
The Northwest Lake has a maximum depth of 5m. It continues in a second room measuring 85 X 58m. It is full of water with a maximum depth of 9m. The upper part of this chamber is exposed out of the water.
At the north and south end of the west side of the chamber, there are two siphons that end in impassable narrows, which indicate that the cave continues and is connected to the wider karstic network of the area.
The cave also continues underwater to the southeast lake at a maximum depth of 4m with a siphon about 50m long, with a maximum depth of 7m.
The water temperature is constant at 14 degrees Celsius all year, and the clarity of the water is unique, exceeding 40m. of visibility.
As is the case with all the siphons in the area, the lakes’ bottom is covered with at least 10 cm of mud.
The water of the lakes of Zervati is brackish. This is attributed to its groundwater communication, with the caves Melissani and Agalaki, whose waters eventually flow into the springs of Karavomylos.
We warmly thank the Aquatic Scuba Diving Club and Makis Sotiropoulos for supporting our mission in Kefalonia. We hope to return soon for a series of new explorations in this extraordinary geological place.