These thermal baths are particularly popular with visitors and have helpful, English-speaking attendants. There are 15 indoor thermal pools (water temperatures up to 40°C) and three outdoor pools, including an activity pool with whirlpool. The baths are open year-round, and it's quite a sight to watch men and women playing chess on floating boards when it's snowing.
Since all pool facilities are open to both men and women at all times, bathing suits (bring your own or hire one here for 1000Ft) must be worn. If you wish to do lane swimming, you must wear a bathing cap (available for purchase here for 200Ft), and it's a really good idea to bring flip-flops.
The water in the thermal pools, high in calcium, magnesium and hydrogen carbonate, is deemed to be good for pains in the joints, arthritis, blood circulation and disorders of the nervous system. You're not supposed to stay in the hottest thermal pool for more than 20 minutes at a time for health reasons.
Use of the three outdoor thermal pools at the Széchenyi is included in the general admission fee. The whirlpool and Jacuzzi jets in the outdoor pool are enormous fun. The baths host club nights, appropriately named Sparty (get it?), every Saturday.