The Winter Palace is a palace in the "Six Palace Complex" of the National Museum of Russia's Hermitage Museum. is located on the Palace Square in St. Petersburg. It was once the palace of the Russian Empire Tsar. After the October Revolution, it was replaced by the St. Petersburg State Hermitage Museum. The Hermitage Museum (Winter Palace), together with the British Museum in London, the Louvre in Paris, and the Metropolitan Museum of Art in New York, is known as the world's four major museums. The museum was originally a private museum of the Russian Empress Ekaterina II.