Caracalla Therme, Baden-Baden

Bathers soak under the glass dome of Caracalla Therme, the swimsuit thermal spa that opened in Baden-Baden in 1985. Its water comes from the town's hot springs, which reach up to 68°C (154°F) at the source, and the pools range from 18 to 38°C (64 to 100°F). Those who want the older ritual can walk to the nearby Friedrichsbad, an 1877 bathhouse where bathers follow a 17-station Roman-Irish circuit without swimsuits.