Anheuser-Busch's flagship brewery in Soulard has been on the same site since 1860 and is now the largest brewery in the United States. Free tours run daily through the historic brewhouse — a Romanesque pile with stained-glass windows and hops cast in bronze on the brass railings. You see the bottling line, the lager cellars, and the home of the Budweiser Clydesdales, the brewery's iconic draft horses.
The tour ends with two free beer samples in the hospitality room. The 19th-century buildings on the south end of the complex are designated National Historic Landmarks. Book in advance during summer; tours fill quickly. A premium Brewmaster's Tour costs more and goes further behind the scenes.