Dive into the fascinating world of the Opéra Garnier, which was designed by Napoleon III, and built by Charles Garnier, a young architect with little experience who became known internationally by Gaston Leroux and his Phantom of the Opera. A symbol of Paris, it is the only active theatre in the world to be both a place of art as well as a magnificent building bursting with history. As always, the Opera house today is itself an artwork and a true architectural gem, with its imperial crown dome fancy theater curtain through which one can glide to reach the grand staircase. Under the Palais Garnier dome, among the gilding and red velvet, the monumental fresco by Marc Chagall is striking and unusual in its modernity. The windows of the Grand Foyer, overlooking the avenue are every bit as good as the Hall of Mirrors at Versailles. The Opéra Garnier is an architectural masterpiece and an absolute must-see.