The Moskva River (, Moskva-reka), also known as the Moscow River, is a river of western Russia. It rises about west of Moscow, and flows roughly east through the Smolensk and Moscow Oblasts, passing through central Moscow. About south east of Moscow, at the city of Kolomna, it flows into the Oka River, itself a tributary of the Volga, which ultimately flows into the Caspian Sea.