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 Balaton the late 19th century when landowners, ruined by "Phylloxera" attacking their grape vines, began building summer homes to rent out to the burgeoning middle classes. In Hungarian, the lake is known simply as "Balaton". It was called "lacus Pelsodis" or "Pelso" by the Romans. The name is Indo-European in origin (cf. Czech "pleso" ‘sinkhole, deep end of a lake’), later replaced by the Slavic *"bolto" (Czech "bláto", Slovak "blato", Polish "błoto") meaning 'mud, swamp' (from earlier Proto-Slavic "boltьno", , ). Slavic prince Pribina began to build in January 846 a fortress as his seat of power and several churches in