The balroom of the Catherine Palace, Tsarskoe Selo, Russia. Designed by Italian Architect Francesco Bartolomeo Rastrelli - Court Architect to Empress Elizabeth and master of the Russian Rococo/Late Baroque style.
Le Palais Garnier, Opera House, in Paris. Marc Chagall's fabulous artwork covers the ceiling. (This is the opera house on which The Phantom of the Opera is based . supposedly there is a real lake underneath!