Lake Hévíz among Rotatorias as well ("Epiphanes brachionus" var. "Spinosus", "Lecane inermis"), which are only present in warm waters. Jenő Ponyi has described the lake's primitive crustaceans in detail. Also a unique "Hydracarina acarus" is said to have found its habitat outside the fence surrounding the lake. The waters are reported to be beneficial to patients suffering from rheumatic diseases and locomotor disorders, among others. There is a thriving health tourism industry in the area. Lake Hévíz Lake Hévíz is located in Hévíz, Hungary, near the western end of Lake Balaton, from Keszthely. It is the largest thermal lake in the world,
Lake Constance St. Gallen, and Schaffhausen. The Rhine flows into the lake from the south, with its original course forming the Austro-Swiss border, and has its outflow on the "Lower Lake" where — except for Schaffhausen — it forms the German-Swiss border until the city of Basel. Lake Constance is the third largest freshwater lake in Central and Western Europe in terms of surface area (and the second largest in terms of volume), after Lake Geneva and (in terms of surface area) Lake Balaton. It is long, and at its widest point, nearly wide. It covers approximately , and is above sea