Melissani Cave or Melissani Lake, also Melisani is a cave located on the island of Kefalonia, northwest of Sami, about 5 km SE of Agia Efthymia, NE of Argostoli and NW of Poros. The Ionian Sea lies to the east with the Strait of Ithaca. Forests surrounds the cave and the mountain slope is to the west. Near the cave is the entry to the cave with parking lots and is passed almost in the middle of the main road linking Sami and Agia Efimia especially to the northern part of the island.
In Greek mythology, Melissani was the Cave of the Nymphs. It features a lake surrounded with trees and forest, and is located east of the mountains of Evmorfia and Agia Dynati. Tourism is common.
The lake's bottom is covered with stones. Plants grow at the opening of the cave. The color of the stone near the opening is stucco to honey-like brown.
The cave was rediscovered in 1951 by Giannis Petrocheilos.