The Cave of Melissani is one of the most interesting caves in Kefalonia. Situated just outside Sami, there has trees and forests surrounding, even a lake. The cave is 3.5 km long, 40m wide and 36m high. Melissani cave constitutes a unique geological phenomenon. It was created by a mechanical and chemical process called karstikopoiisi (dissolution of rocks) during which water enters the calcareous rocks, erodes them and creates hollows.
The lake includes also an islet on which archeologist S. Marinatos discovered Pan's sanctuary. The findings you can find  in the Archeological Museum of Argostoli. These findings include a clay figure of Pan, a clay disc depicting dancing nymphs, a clay plate depicting the procession of nymphs and a small plate with a woman figure relief.
Visitors reach the lake by an underground tunnel and can explore it with a boat and a guide.