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.
Brigach
The Brigach is the shorter of two streams that jointly form the river Danube in Baden-Württemberg, Germany. The Brigach has its source at above sea level within St. Georgen in the Black Forest. The Brigach crosses the city Villingen-Schwenningen. from the source, the Brigach joins the Breg in Donaueschingen to form the Danube River.