Therme Bucuresti is a huge thermal spa and water complex north of the city, close to the airport road. Palms, warm pools, saunas, slides, and relaxation areas make it one of Bucharest's most popular modern leisure attractions.
It is not a historic sight, but it is useful if you want a break from traffic, museums, and old-town bars. Families, spa-goers, and travellers with a late flight may find it especially practical.