Which river is Europe's longest, at about 3,690 km?

Europe’s longest river, at about 3,690 km, is the Volga.

The Volga rises in the Valdai Hills northwest of Moscow and flows south through European Russia before emptying into the Caspian Sea. Its basin covers much of western Russia, and the river passes near major cities including Tver, Nizhny Novgorod, Kazan, Samara and Volgograd.

The Volga is entirely within Russia, unlike the Danube, which crosses or borders ten countries. The Danube is Europe’s second-longest river at roughly 2,860 km. The Ural is another common mix-up: it helps form a conventional boundary between Europe and Asia, but is substantially shorter than the Volga.

The river is also central to Russian history, transport and industry. Large reservoirs and hydroelectric dams now regulate much of its course, while its delta is an important wetland on the northern Caspian shore.