Lake Hévíz

Lake Hévíz
Medicinal Bath of Hévíz
Location	Hévíz
Coordinates	46°47′14″N 17°11′35″E / 46.78722°N 17.19306°E / 46.78722; 17.19306Coordinates: 46°47′14″N 17°11′35″E / 46.78722°N 17.19306°E / 46.78722; 17.19306
Basin countries	Hungary
Surface area	47,500 m2 (511,000 sq ft)
Residence time	72 hours

Lake Hévíz is located in Hévíz, Hungary, near the western end of Lake Balaton, 8 kilometres (5 mi) from Keszthely.

It is the largest thermal lake in the world, which is available to bath. (47,500 square metres (511,286 sq ft) in area). The flow of water is very strong and the water in the lake is completely replenished in every 72 hours.

The fauna and flora are unique in Lake Hévíz due to the temperature and chemical composition of the water, contains carbonic acid, calcium, magnesium, hydrogen carbonate, reduced sulfuric compounds as well as oxygen in solution. Several species so far can be found only in this lake.

Bacteria is the dominant life form in the lake; it is possible that this is a cause of the curative effect. Several taxa can be found here. Most common Cyanobacteria are filamentous blue-green algae (Oscillatoria princeps, O. tenuis, O. jasoruensis, O. chlorina, Spirulina major). It is interesting to note that half of the blue species are thermophile, stenoterm ones. There are two thermophile blue green alga species (Pseudanabaena papillaterminata, Pseudanabaena crassa) of which Lake Hévíz is the only Hungarian habitat.

Bacterial tektons are typical of the lake. The crater is covered mostly by Thiothrix sp. and Beggiatoa sp. from a depth of 1.5 m to the opening of the springcave. These together with the bacterium species play an important role in the lake's sulfur cycle.