Danube River

The Danube River is the second-longest river in Europe, after the Volga in Russia. It flows through much of Central and Southeastern Europe, from the Black Forest south into the Black Sea. In the 21st century, it connects ten European countries, running through their territories or marking a border. Originating in Germany, the Danube flows southeast for 2,850 km (1,770 mi), passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and Ukraine. Among the many cities on the river are four national capitals: Vienna, Bratislava, Budapest, and Belgrade. Its drainage basin amounts to 817,000 km² and extends into nine more countries.

Today, 2,415 km (1,501 mi) of its total length are navigable. The Danube is linked to the North Sea via the Rhine–Main–Danube Canal, connecting the Danube at Kelheim with the Main at Bamberg. The river is also an important source of hydropower and drinking water.

Navigation is monitored by the Danube Commission.