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.
The Ister (film)
Eventually the film arrives at Donaueschingen, and at the Breg and the Brigach, the two tributaries whose confluence marks the point at which the river becomes known as the Danube. The film then travels upstream along the Breg, past Vöhrenbach and Furtwangen, in search of the "true" mountain source of the Danube.