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-Auen National Park
Until the 19th century the Danube was an untamed river. In the 19th century, extensive engineering began to alter the natural balance of the river landscape dramatically. Many side-channels were dammed so that they now carry water from the Danube only at flood stages. Ever more intrusive engineering interventions were accompanied by decades of heavy forestry use in many parts of lowland forests. In the 1950s, development began of an nearly unbroken chain of hydroelectric power plants and associated dams on the Austrian section of the Danube River.