Gellért Termálfürdő
At the foot of Gellért Hill, the gorgeous Gellért Baths has beauty and history in spades, with hot springs that have supplied curative baths for nearly 2,000 years. The entrance to the spa is on a side street to the right of the palatial Danubius Hotel Gellért, although the pair are no longer run by the same company. These baths are unsurprisingly popular among tourists so you will want to book ahead online. Budapest's baths, once segregated, are now primarily co-ed (with special hours for segregated bathing for some baths), and it's the same story here. Men and women can now use all steam and sauna rooms as well as both the indoor pool and the outdoor wave pool—a Jazz Age classic that claims to be one of the first wave pools in the world—at the same time. Come for the lovely tiles, architecture, and painted glass, and stay for the range of treatments (some of which require a doctor's prescription).