The cave spans three distinct levels created by the gradual erosion of the limestone rock by the subterranean river.
The 13 tiered lakes are formed by natural dams of limestone sinter that hold back the water in terraced steps.
Fossilized remains of a hippopotamus were discovered inside the cave, indicating a significantly different climate in the region during the Pleistocene epoch.
The cave serves as an active drainage basin; the water level is significantly higher during the winter and spring runoff periods.
Artificial concrete bridges were installed in the 1980s to allow tourist access to the lake levels without damaging the delicate floor formations.
The temperature inside the cave remains constant at approximately 16 degrees Celsius throughout the year.
Cave of the Lakes, or Kastria Cave, is a rare geological formation in the Peloponnese peninsula featuring 13 tiered cascading subterranean lakes. The cave system spans 1,980 meters, though visitors traverse a 500-meter accessible path via artificial bridges. The cave is the natural sinkhole of the Aroanios River, which feeds the lakes through a series of geological strata. A small artificial tunnel leads into the main chambers, where water level fluctuations create diverse stalactite and stalagmite formations. During winter, the cave exhibits a subterranean waterfall system, while dry seasons reveal the distinct limestone terraces of the lake beds. The site is a protected geological monument managed by the Municipality of Kalavryta. It serves as a natural habitat for several species of micro-fauna adapted to low-light conditions.
The entrance area immediately outside the cave mouth provides a view of the surrounding mountain landscape.
Wear footwear with high-traction soles, as the metal and concrete walkways can become slippery due to high humidity.
Bring a light jacket even in summer; the interior temperature is significantly cooler than the external mountain air.
Check official local updates before arrival, as heavy rainfall can occasionally lead to temporary closures for safety.
Do not attempt to walk off the designated path or touch the stalactites, as oils from human skin permanently inhibit their growth.
The site remains open year-round, though visitor access to deeper sections may be restricted based on seasonal water levels.
Photography is strictly prohibited inside the cave to protect light-sensitive geological formations; touching the cave walls is forbidden.
