Opera Garnier
Ceiling by Chagall, commissioned by Napoleon III and built in a gorgeous neoclassical style, this can be visited from 10-4:30 every day of the week. In 1989, a second, modern opera house opened at the Bastille. Use the website if you want to buy tickets to a performance. There are well-priced last minute seats for those under age 28 on the day of the performance.
Opera Garnier
Corner of rue Scribe and rue Auber
Map it!
Metro: Opera
website: www.operadeparis.fr