Oka River

Oka River

Oka (Russian: Ока́, ) is a river in central Russia, the largest right tributary of the Volga. It flows through the regions of Oryol, Tula, Kaluga, Moscow, Ryazan, Vladimir, and Nizhny Novgorod and is navigable over a large part of its total length, as far upstream as to the town of Kaluga. Its length exceeds 1,500 kilometres (930 mi). The Russian capital Moscow sits on one of the Oka's tributaries—the Moskva River.