Thermal Lake of Hévíz

The Thermal Lake of Hévíz is built around one of Europe's largest natural thermal lakes, a nearly 250-meter-wide basin formed over a karst spring. At its center a 40-meter-deep crater feeds the lake through a spring cave roughly 17 meters across and 14 meters high — first explored by divers in 1975. The site is run by the Hévíz Szent András Reumakórház és Gyógyfürdő, a facility that combines the lake with a hospital-grade medical program.

Treatments here lean medical rather than recreational. Options include Hévíz medicinal mud (gyógyiszap), weight baths (súlyfürdő), underwater water-jet massage (tangentor), medical massage, physiotherapy (gyógytorna), and a drinking cure (ivókúra) — six treatment types in total. A full course typically starts with a medical exam, after which a doctor sets the treatment plan based on the visitor's condition.

As of early 2025, the central bath building — known as 'A' building and the 'B' terrace, the structure actually sitting over the lake — has been closed to visitors following a structural assessment that found it unsafe for continued use. Anyone planning a visit should check the current state of access before arriving, since this affects how much of the lake experience is available.

The site operates seven days a week, 9:00 to 18:30, with day passes available and online ticket purchase offered through the operator's webshop. Reservations are required for medical treatments. There's also a four-star hotel, Hotel Spa Hévíz, attached to the complex for those staying overnight to complete a longer treatment course.