Moscow is located on the Moskva River in western Russia and is the nation's cosmopolitan capital. In its historic center, there is the Kremlin, a complex that houses the president and treasures of the tsars in the Armory. Outside its walls is Red Square, the symbolic center of Russia. Here is the Lenin Mausoleum, the comprehensive collection of the State Historical Museum and St. Basil's Cathedral, known for its colorful onion domes.