The City Theater (') was built in 1909 by Ferdinand Fellner. By the time of the First World War, Baden was Vienna's principal resort: came each year, double the town's local population. In addition to a modern "spa house" ('), there were 15 separate bathing establishments and several parks. During the war, Baden served as a temporary seat of the Austro-Hungarian high command. A new casino in 1934 made the town the premier resort throughout Austria. The Château Weilburg was destroyed during World War II. After World War II, Baden served as the headquarters of Soviet forces within occupied Austria until 1955.