The lake cave of Melissani is located 2 km northwest of Sami in Kefalonia.
The natural entrance of the cave is vertical with dimensions of 40 x 50 m and was created by the fall of a part of the roof. Artificial entrance with stairs and a long underground corridor allows a visit to the cave.
The lake is located 20 m below the ground surface and the depth of its waters ranges from 10 m to 30 m.