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 Donaubach rises on the castle grounds near the left corner of the front face of the castle Donaueschingen in a karst spring. This karst spring has an embankment of 15 to 70 l/s and enters into the Brigach after flowing 90 meters belowground. The Brigach and the Breg become the Danube after 1.5 km. The source is one of 22 sources in the area of the junction of Brigach and Berg. All of these sources are fed by both water which trickles away above them and rainfall which trickles away on the karstified downs of a landscape called Baar. Together, the Brigach and the Breg empty out between 400 and 1000 l/s.