L'Opéra National de Paris is the primary opera house in Paris and it is a gem. It was founded in 1669 and have been kept in pristine condition. Although there are over 300 performances a year, you don't need to actually attend an opera to enjoy this magnificent building. The are guided and unguided tours nearly every day and the many floors of gorgeous rooms and displays can keep you occupied for hours. There is also a very special production of honey that is done on the roof!