Near Kalavryta, in the village of Kastria, Achaia and at an altitude of 800 meters, there is a cave of unique beauty. It is the "Cave of the Lakes".

The cave is an old underground river bed, 1980 meters long. The utilized length of the cave is 500 meters. In the winter when the snow melts, natural waterfalls are created. In the summer when the waters are clear, original basins and dams, up to 4 meters high, are discovered. The rest of the cave maintains permanent waters in 13 picturesque lakes.
The "Cave of Lakes" has something unique that does not exist in other caves. It is its successively scalable lakes, spread over three floors and make it unique in its kind to the world. The ponds are crossed by elevated artificial bridges. You enter the cave by an artificial tunnel, which ends directly on the second floor.
On the lower floor of the cave were fossilized human bones and various animals, including a hippo. This section is intended for a biomedical laboratory of international prominence.
In 1964, residents of Kastria first climbed the second floor with a 9-meter-high staircase. The exploration was done by the Greek Mountaineering Association with Professor I. Melentis and mapping by the Hellenic Speleological Society with Speleologist Anna Petrochilou.