The Palais Garnier (a.k.a. Opéra Garnier and Opéra de Paris) is probably the most famous opera house in the world, no doubt in part due to its setting for the 1910 novel The Phantom of the Opera. Another reason is that, of all the buildings constructed during the Second Empire, this was the most expensive. Due to its exceptional opulence, that fact that would not be surprising for any who tour it. Built from 1861 to 1875 in the Second Empire Beaux-Arts style with Neo-Baroque elements, it is now used principally for ballet.