Moscow, on the Moskva River in western Russia, is the nation's cosmopolitan capital. In its historic core is the Kremlin, a complex that's home to the president and tsarist treasures in the Armoury. Outside its walls is Red Square, Russia's symbolic center. It's home to Lenin's Mausoleum, the State Historical Museum's comprehensive collection and St. Basil's Cathedral, known for its colorful, onion-shaped domes.