Situated on the Athenian Riviera about 20 kilometers south of Athens is a stunning hidden wonderland – Lake Vouliagmeni. Close to one of the best beaches in Athens, this area is a beautiful natural landscape, with a rare geological formation and unique thermal spa in a setting of lush vegetation.
Millions of years ago, the lake was located inside a huge cave and was fed by numerous hot springs and seawater. Following an earthquake in the area, the roof of the cave collapsed, leaving the lake as it is today.
The lake covers an area of two hectares and the water level is 50cm higher than the local sea level. The lake is thought to be 50-100 meters deep and because it is still fed by hot springs and seawater, there is a distinct current that can be felt in the water.
On the far side of the lake there is a rocky cliff face with a cave entrance which leads in to an extensive cave system with 14 tunnels covering 3,123 metres. So far, explorations have not found the furthest point of the rocky labyrinth.
One of the tunnels is 800 meters in length – making it the longest of its kind in the world. This tunnel has a huge stalagmite which has raised questions amongst geologists about the formation of cave and the whole Mediterranean area.