Hévíz Springcave

Hévíz Springcave is an underground chamber located approximately 38 meters beneath the lake surface that feeds warm water into the surrounding lake. It serves as the natural source point where thermal water continuously rises and shapes the water conditions of the entire lake.

People visited the spring source area since ancient times, as Roman artifacts including coins, pottery, and a Jupiter altar demonstrate, dating back to the 1st century. The site remained a place of human activity and veneration across thousands of years.

The spring cave contributes to the thermal waters that have attracted people seeking natural remedies for rheumatic conditions since Roman times.

The cave is accessed underwater, so visitors can explore it best by snorkeling or diving to observe the thermal water source and its surroundings. Water temperatures remain warm year-round, making swimming or exploration enjoyable during most seasons.

The two water layers have different origins: the cold water dates back about 8,000 years, while the hot medicinal water is at least 12,000 years old. These separate sources mix beneath the surface and create the lake's distinctive thermal conditions.