Volga river rises in the Valdai Hills northwest of Moscow, Russia. The Volga discharges into the Caspian Sea. Its river system, comprising 151,000 rivers and permanent and intermittent streams, has a total length of about 357,000 miles. It is the most important waterway in Russia. Cities on the river: Nizhny Novgorod, Kazan, Samara and Volgograd. Ob-Irtysh River is a river of central Russia . One of the greatest rivers of Asia, the Ob flows north and west across western Siberia in a twisting diagonal from its sources in the Altai Mountains to its outlet through the Gulf of Ob into the Kara Sea of the Arctic Ocean. It is the largest river of Russia by volume. Novosibirsk is on Ob. The Irtysh drains into China’s Dsungarian basin. The Yenisey River is the fifth-longest river system in the world , and the largest to drain into the Arctic Ocean . Yenisey River is the river of central Russia . The world’s sixth-largest river in terms of discharge, the Yenisey runs from south to north across the great expanse of central Siberia. Cities on river: Bratsk, Ulan-Ude and Krasnoyarsk on Yenisei. The Lena River is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean . City on river: Yakutsk on Lena The Lena is the eleventh-longest river in the world.