The most breathtaking subway exit in the world may be the one at Place de l’Opéra in Paris. Its final steps lead to a postcard-ready view of the sensational Palais Garnier, the love-it-or-hate-it theater with a Baroque, Renaissance and all-around garish pastiche that overwhelms and enchants at every turn.

It was designed by Charles Garnier — you can find a gaudy monument to him outside — and built between 1861 and 1875. Until 1989, it housed both the Paris Opera and the Paris Opera Ballet, until nearly all the opera productions moved to the Garnier’s antithesis: the coldly modern, widely reviled Opéra Bastille.

But the Garnier has always been so much more than just an opera house. It’s essential to the identity of Paris, like the Notre-Dame or Arc de Triomphe. It has transcended further to the realm of pop culture, inspiring Gaston Leroux’s 1910 potboiler novel “The Phantom of the Opera” — and the 1980s Andrew Lloyd Webber megamusical, adding to the thriller an over-the-topness matched only by the opera house itself.