In Paris, get off the Metro station "Opéra". There are two operas in Paris, Garnier (this one, the historical) and Bastille (modern one).
Photo Spot Details
Paris is a wonderful city, but I think it is even better at night. Among all the monuments in Paris, one of my favorite is this one. During the day you can visit it and it is worth doing it (at least for the ceiling painted by Chagall). During the night the beauty of the building is even more explicit. Bring tripod, wide-angle and tele lenses.