Cave of Agia Sofia.

The cave of Agia Sofia is situated in a steep rock 60 m. high, outside Milopotamos, 15 km, northwest of Kythera. It is one of the most beautiful Greek caves. It was named after the chapel of Agia Sofia, which stands at the cave's entrance. The chapel was built in 1785 in honour of Agia Sofia, whose corpse is said to have been found here. The cave's interior is separated into numerous chambers. In the chamber where the chapel is one can admire a small lake with beautifully coloured water. The walls are covered with lovely stalactites and stalagmites of several sizes, as well as amazing murals from the 11th and 12th centuries. The chambers have names which refer to the colour and shape of the stalactites, such as "Venus's Chambers and Bathroom". There are also the Chambers of Ambers, of Pearls, of Bats, of Pine trees and of Leo.

http://www.hri.org/infoxenios/english/ionian/kythera/sights.html