Cave of the Lakes

The Cave of the Lakes, formerly called Troupisio, is located near the village Kastria in the municipality of Kalavryta, Achaea regional unit. It is 17 km from Kalavryta and 9 km from Kleitoria.

The cave is an old subterranean river consisting of three levels. During the winter when the snow melts it is transformed into a flowing river with waterfalls. During the summer, it dries up, leaving behind 13 lakes.

Source: Wikipedia