This is the best sight on the entire island of Kefalonia (and for me it was the best amongst all the places I have ever visited!). No I am not exaggerating and I am sure that you will say the same once you visit the place. The cave is shaped in form of the letter B and is about 40 meters wide and 36 meters high...
But who's interested in statistics... it is the beauty of the place that definitely deserves a visit. The full tour is done by boat, first making an encompassing trip around the first hall of the cave with the crack in the roof. After that the boat crosses the island on the opposite wall, where a tiny canal exists. This channel is too slender for the boat to row, and therefore there is a rope attached to the wall with which the gondolier pulls the boat.
It was a very good experience. There are numerous stalactites and stalagmites in the second chamber of the cave and when the boat passes it, numerous lights lit up the place which was simply outstanding. Highly recommended.