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.
Source of the Danube
The Danube is conventionally taken to be formed by the confluence of the two streams Brigach and Breg just east of Donaueschingen.
The source of the Donaubach, which flows into the Danube, in Donaueschingen is often referred to as the source of the Danube ("Donauquelle"). Hydrologically, the source of the Danube is the source of the Breg as the larger of the two formative streams, which rises near Furtwangen.