Baden-Baden, Germany, a city in the state of Baden-Württemberg. It is about 30 miles (48 km) north-northeast of Strasbourg, France. Baden-Baden is the most popular spa and tourist center in the Black Forest. Its hot mineral springs, with temperatures ranging from 130° to 150° F. (54° to 66° C.), have been known since the times of ancient Rome. (Badenis the German word for "bathe.") Remains of old Roman baths are still to be seen. There are several castles in the old section of town.