The document provides information about various opera houses around the world. It describes the architectural features and histories of opera houses in cities such as Amsterdam, Brussels, Budapest, Buenos Aires, Copenhagen, Frankfurt, London, Madrid, Milan, Moscow, New York, Oslo, Paris, Prague, São Paulo, Sofia, St. Petersburg, Stockholm, Vienna, and Sydney. Specific details mentioned include opening dates, inaugural performances, interior designs, and notable architectural aspects like chandeliers. Photographs and links to enlarged photos of some of the opera houses are also provided.