Moscow is the most northern city on Earth situated on the Moskva River in the central Russia. In the course of its history the city has served as the capital of a progression of states, from the medieval Grand Duchy of Moscow and the subsequent Tsardom of Russia to the Soviet Union. Moscow is the site of the Moscow Kremlin, an ancient fortress that is today the residence of the Russian President and of the executive branch of the Government of Russia. The Kremlin is also one of several World Heritage Sites in the city.
Over time, Moscow has acquired a number of epithets, most referring to its size and preeminent status within the nation: The Third Rome , Whitestone , The First Throne , The Forty Forties .In old Russian the word"" (''forty'') also meant a church administrative district, which consisted of about forty churches.