Charles Garnier's 1875 palace consumed thirty-five tonnes of bronze, eight types of marble and fourteen years of uninterrupted construction — Napoleon III never lived to see its first curtain. The Second Empire architect layered every surface with gilt, allegorical sculpture and polychrome stone, creating what critic Théophile Gautier called "a temple to art disguised as an opera house." Today the Palais Garnier anchors the Opéra de Paris alongside the modernist Bastille theatre, hosting ballet performances while opening its public spaces to daytime visitors. The five-tiered auditorium seats 1,979 beneath Marc Chagall's 1964 ceiling fresco — a commission that sparked fierce debate when installed over Jules-Eugène Lenepveu's original Second Empire cartouches. Chagall's dreamlike panels honour fourteen composers from Mozart to Berlioz, their colours deliberately chosen to contrast Garnier's gold-and-crimson scheme. The six-tonne bronze chandelier descends from the centre, its 340 lights powered by gas when first installed. In 1896 one of its counterweights fell through the ceiling during a performance of Hellé, killing a concierge in her seat — the real incident Gaston Leroux wove into *Phantom of the Opera* thirty years later. Garnier integrated thirty foyers, rotundas and salons into the structure, transforming intermission into architectural promenade. The Grand Foyer stretches fifty-four metres along the western façade, its barrel-vaulted ceiling covered in gilt mosaics depicting musical allegories. Paired ionic columns frame twenty arched mirrors, each reflecting light from bronze candelabra and crystal chandeliers. The marble Grand Staircase divides at its first landing, white Carrara stone contrasting with green Swedish marble balustrades and onyx pedestals. Two monumental bronze torchères — La Musique Instrumentale and La Musique Vocale — flank the entrance, cast by Hippolyte Moulin. Paris Opera House self guided tour tickets grant access to the public galleries, auditorium viewing box, permanent collection of costume sketches and the library-museum's rotating exhibitions. Guided options include theatrical backstage routes and arts-historian-led deep dives into Garnier's symbolist decoration. The palace occupies three acres between Boulevard des Capucines and Rue Auber, its gilded rooftop sculpture Apollo, Poetry and Music visible from the surrounding arrondissement.