The medicinal water in Harkány that arises from 50-70 m depth is unique in Europe. The temperature of the water discharging from the supply wells is around 62 ºC; its mineral content exceeds 1 000 mg/l. From therapeutic point of view the most valuable component in the water is the bivalent sulphur compound carbonic sulphide (COS) which is a gas and is in solution under pressure in the water. When the water reaches the surface, the gas is released from the pressure and immediately begins to decompose; it turns into hydrogen sulphide gas, which is responsible for the characteristic odour of the water. In a side-light, the precipitated tiny grains of elementary sulphur can be visible to the naked eye in the pools.
Regarding the alkali hydrogen carbonate composition and high sulphide content, the medicinal water in Harkány is unique in Europe.
In the beginning there were sulphur-springs feeding moorlands in the land of the recent town, therefore sulphurous water naturally arose to the surface. According to the legend, a serf observed the healing character of the water during working on the drainage of the area; his leg recovered as he was standing in the hot water all day long. The first written document on the healing nature of Harkány medicinal water dates back to 1823.
In the completely refurbished medicinal bath an indoor, a half-covered, and an outdoor pool await the guests with a total water surface area of 2098 m2, depth of 110-153 cm and water temperature of 34-38 ºC.
The composition and quantity of the valuable medicinal water must be protected. Determination of the protection zones was carried out in the cooperation of SMARAGD-GSH Ltd. and MECSEKÉRC Co. Ltd. in 2008. Next to the safety plan of the water supply we paid attention to the quantity of groundwater resources and the groundwater flow conditions in the Southern Baranya Region (area between Villány Mountains and Dráva Basin).