It may be a cliche but a visit to a spa or thermal bath really is a "must-do" when in Budapest. Hungary is awash with thermal springs and there are a number of spas that are open to the throngs of curious tourists.
Located on the Pest side of the Danube, the Széchenyi Baths are one of the most famous spas in Budapest - famed for the images of men playing chess in the steaming waters! Ease your joints in the mineral rich waters, have a sauna, enjoy a mud-pack or just a swim or simply kick back and relax and take the opportunity people-watch. Remember that these baths are mixed and swimming costumes must be worn at all times! To get to Széchenyi Baths, you can take the underground (line M1) and alight at the Széchenyi fürdo station.
Another spa worth checking out is the stunning art-nouveau Gellért Baths also in Pest, at the Hotel Gellért. This beautiful spa has stained glass windows, mosaic floors and stunning wooden changing rooms. Unlike the Széchenyi Baths, the Gellért Baths are not all mixed and there are six single sex pools (three for the ladies and three for the gents). Costumes are therefore optional so be warned if you are of a sensitive disposition! To get to the Gellért Baths, you can take a tram (numbers 19,47 or 49) to Szt. Gellért tér station.