The Gellert Baths at the Danubius Hotel Gellert (in the Gellert-Hegy area, opposite the market place and Szabadsag, raven-topped bridge) are a must. Probably Budapest's most famous and almost certainly the most beautiful and elegant, they comprise indoor pools, thermal baths, an outdoor wave pool (summer months only) and all kinds of treatments (mudpacks, massages, facials, pedicures, etc.). Budapest has been a spa town since the Turkish occupation, its waters valued for their medicinal qualities. Medicinal or not, one of my favourite memories will always be sitting in the warm thermal waters whilst gazing up at the stained glass ceiling with a flow of warm water beating on my shoulders and swimming in the indoor swimming pool, surrounded by marble columns and mosaic flooring).
Constructed in 1913, the Gellert tries to maintain its traditions of style and service, dating from the era of Emperor Franz Josef. It’s more expensive than the city’s other baths (though it won't break the bank) and you can visit even if you are not staying in the hotel. Many visitors are indeed tourists but it's definitely a favourite haunt of some local ladies as well.
There's little room for prudery or indeed much modesty at the Gellert but somehow your own inhibitions melt away alongside the locals’. On entering, men receive a strip of cloth, women a tiny apron (though many women don’t bother – apparently the men are more private and generally make the most of the fabric strip). Once inside and familiarised with your surroundings and the moist heat, you can take a massages (the short ones last 15 minutes, the more thorough, lasting 40 minutes, is an altogether more vigorous experience not to be embarked upon by the faint-hearted - other treatments happen outside so you'll have to get dressed). To the sides of the 2 thermal baths are separate steam rooms and saunas.
Swimsuits on for the main (mixed) swimming pool, a glorious Art Nouveau beauty surrounded by a colonnade of amber porcelain with water gushing from the mouths of blue dragons into the pool. Swans spread their wings across a mosaic floor, and flora and fauna mix in a riot of colour across a gallery of stained glass windows. There's an unforced hushed peace, broken only by the splashing of swimmers, the continual gushing of mineral water and the gentle human sighs of contented relaxation.
Pool May-Sept daily 6am-7pm (July-Aug also Fri-Sat 8pm-midnight); Oct-April Mon-Fri 6am-7pm, Sat-Sun 6am-5pm. Pool&baths 6-6 daily. Entry - 2700Ft (money back if you leave within 2 hours).