List of tributaries of the Danube
The Danube is Europe's second-longest river. It starts in the Black Forest in Germany as two smaller rivers—the Brigach and the Breg—which join at Donaueschingen, and it is from here that it is known as the Danube, flowing generally eastwards for a distance of some , passing through several Central and Eastern European capitals, before emptying into the Black Sea via the Danube Delta in Romania.
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.