The Kremlin is a fortified complex in the centre of Moscow founded by the ruling dynasty of Rurikids. It is the best known of the kremlins, and includes five palaces, four cathedrals, and the enclosing Kremlin Wall with Kremlin towers. In addition, within this complex is the Grand Kremlin Palace that was formerly the Tsar's Moscow residence. The complex now serves as the official residence of the President of the Russian Federation and as a museum with almost 3 million visitors in 2017. The Kremlin overlooks the Moskva River to the south, Saint Basil's Cathedral and Red Square to the east, and the Alexander Garden to the west. The name "Kremlin" means "fortress inside a city", and is often also used metonymically to refer to the government of the Russian Federation. It previously referred to the government of the Soviet Union and its highest members. The term "Kremlinology" refers to the study of Soviet and Russian politics.