Saint-Petersburg is one of the main cultural and historical centers of Russia, founded in 1703 by Peter the Great and known for its canals and bridges. It contains many outstanding monuments, including St. Isaac's Cathedral, Kazan Cathedral, Peter and Paul Fortress, the Hermitage museum, and Smolny Cathedral. The Hermitage museum houses over two million works of art from different eras and cultures. St. Peter and Paul Cathedral's bell tower marks the consolidation of the new capital and contains the tombs of Russian emperors from Peter I to Nicholas II.