Hévíz

Hévíz in western Hungary near Lake Balaton is home to the world's largest biologically active natural thermal lake, a 4.4-hectare surface of sulphurous spring water emerging at 33-38°C from a volcanic cave at the bottom of the lake, creating a year-round open-air bathing environment carpeted in lotus flowers and visited by over a million bathers annually. The lake's remarkable biological system — fed by 80 million litres of water daily that completely replaces itself every 28 hours — maintains a temperature mild enough for swimming even in winter, creating the extraordinary spectacle of bathers among snow-covered lotus beds. Hévíz, settled by Romans as Aquae Calidae, has been one of Europe's premier thermal resorts since the 18th century and continues to attract visitors seeking the simply unparalleled experience of swimming in this remarkable natural thermal lake.