The largest thermal lake in the world that is suitable for bathing is located at Hévíz, in western Hungary. The water temperature never drop below 79°F/26°C – even in the depths of winter – and the lake is surrounded by hotels and sanatoria.
Miskolctapolca, in the northeast of the country, boasts a unique cave lake. Situated on a geological fault line on the edge of the Bükk Hills, it is the site of both cold karst- and hot-water springs.
There is also a new spa hotel at Egerszalók; the steaming terraces of snow-white calcium crystals on the green hillside are a spectacle to behold.