Moscow is the capital and most populous city of Russia, with 13.2 million residents within the city limits, 17 million within the urban area and 20 million within the metropolitan area. Moscow is one of Russia's federal cities.
Moscow is the seat of power of the Government of Russia, being the site of the Moscow Kremlin, a medieval city-fortress that is today the residence for work of the President of Russia. The Moscow Kremlin and Red Square are also one of several World Heritage Sites in the city. Both chambers of the Russian parliament (the State Duma and the Federation Council) also sit in the city. Moscow is considered the center of Russian culture, having served as the home of Russian artists, scientists, and sports figures and because of the presence of museums, academic and political institutions and theatres.
The city is served by a transit network, which includes four international airports, nine railway terminals, numerous trams, a monorail system and one of the deepest underground rapid transit systems in the world, the Moscow Metro, the fourth-largest in the world and largest outside Asia in terms of passenger numbers, and the busiest in Europe. It is recognized as one of the city's landmarks due to the rich architecture of its 200 stations.