Danube
Classified as an international waterway, it originates in the town of Donaueschingen, in the Black Forest of Germany, at the confluence of the rivers Brigach and Breg. The Danube then flows southeast for about , passing through four capital cities (Vienna, Bratislava, Budapest and Belgrade) before emptying into the Black Sea via the Danube Delta in Romania and Ukraine.
Danube
There are three artificial waterways built on the Danube: the Danube-Tisa-Danube Canal (DTD) in the Banat and Bačka regions (Vojvodina, northern province of Serbia); the Danube-Black Sea Canal, between Cernavodă and Constanța (Romania) finished in 1984, shortens the distance to the Black Sea by ; the Rhine–Main–Danube Canal is about , finished in 1992, linking the North Sea to the Black Sea.