The largest therapeutic thermal baths in Europe are located in Budapest, the capital of Hungary, and are known as the Széchenyi Baths (Széchenyi-gyógyfürd). Two thermal springs that have temperatures of 74 °F (25 °C) and 77 °F, respectively, provide its water. Their name has a Széchenyi-esque ring to it.

These thermal waters mostly contain calcium sulphate, magnesium, and bicarbonate, along with considerable amounts of fluorine and metaboric acid. These waters are recommended medically for a variety of orthopaedic and traumatology therapies, including degenerative joint illnesses, chronic and sub-acute joint inflammations, and sub-acute joint inflammations.

These baths are situated in City Park, and the neo-baroque structures housing them were constructed in 1913, following the architect Gyz Czigler's designs. Men's and women's steam bath areas with private tubs were available at the time, along with a public bathing area.

The complex currently features 3 outdoor pools and 15 indoor pools after being extended in 1927. A new well was bored since the original thermal artesian well, which had expanded, could no longer fulfil its function. In 1938, the second thermal spring was finished.

Today, practically the entire complex is open to the public, and the spa offers the option of renting or buying towels and swimwear. The attendance is higher on the weekends and on holidays than it is during the workweek.

Additionally, a station on the yellow M1 line of the Budapest Metro bears the name of the baths (Millennium underground).