Melissani Cave or Melissani Lake, is a cave located on the island of Kefalonia, northwest of Sami. It is a unique geological phenomenon rediscovered in 1951. In Greek mythology Melissani was the Cave of the Nymphs. The artifacts were found confirm the ritual function of the cave in antiquity.
The lake's bottom is covered with stones and several plants grow at the opening of the cave. Stalactites with an age of 20.000 years and odd shapes adorn most of the cave. Some say the water is so clear that the boats look like they are floating.