Maison de la Radio et de la Musique
Headquarters to France's state broadcasting company, this imposing, circular, 1963 building is more than 500 yards in circumference. It's said to have more floor space than any other building in the country and features a 200-foot tower that overlooks the Seine. Radio France sponsors 100-plus concerts a year, including performances by its own Orchestre Philharmonique de Radio France and the Orchestre National de France. Though the concerts take place at venues throughout the city, a great number are held here, and they're generally inexpensive. French-only building tours are offered on various days at various times. Check the website for current information.