The river in the middle of the Russian plain in part of Europe is the secondary tributary of the Oka River, a tributary of the Volga River. It comes from the southwest of the Moscow hills, and the winding southeast flow through Moscow and is injected into the Oka River. It is 502 kilometers long and has a basin area of 1.8 10,000 square kilometers. North of the Moscow Canal connected to the Volga River, the canal starting point below the navigation, there are many water conservancy hubs, which is of great significance to Moscow's water supply.