When in Paris, make sure you check out Opera Garnier (a.k.a Palais Garnier), named after it's architect Charles Garnier. The sense of grandiose you get once you enter the theater is incredible. I must commend how well this 1875 theater is maintained till date. The 2400 sqft ceiling painted on fresco by Chagall in 1964 must not be missed.
Till next time,
Sagar