Moscow is the capital city and the most populous federal subject of Russia. The city is a major political, economic, cultural and scientific center in Russia and in Europe. Based on Forbes 2011, Moscow has the largest community of billionaires in the world.
Moscow is the northernmost megacity on Earth, the second most populous city in Europe, after Istanbul, and the 5th largest city proper in the world. It's also the largest city in Russia with a population, according to the 2010 Census, of 11,503,501 people.
Moscow is situated on the Moskva River in the Central Federal District of European 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. Both chambers of the Russian parliament (the State Duma and the Federation Council) also sit in Moscow.