The setting of Gaston Leroux's novel "The Phantom of the Opera" is the Paris Opera House. The building itself, known as the Palais Garnier, was built between 1861 and 1875.
Much of the original setting that inspired "The Phantom of the Opera" still exists at the Palais Garnier. Pierre Vidal, the curator of the Palais Garnier’s museum and library, said in a 2010 interview with The Telegraph that the subterranean lake where the story's climax takes place is really just an enormous stone water tank created after several failures to pump the site dry. Vidal explained, "The pressure of the water in the tank stops any more rising up through the foundations, and the weight of the tank stabilizes the building."