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–Oder Canal
The Danube–Oder Canal (; ) is a planned and partially constructed artificial waterway in the Lobau floodplain of the Danube at Vienna, that was supposed to stretch along the Morava River to the Oder at the city of Kędzierzyn-Koźle in Poland.