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.
Friedberger Ach
The Friedberger Ach is a river in Bavaria, Germany. It is a right tributary of the Danube. Its source is in the village Untermühlhausen, northeast of Landsberg am Lech. For most of its length it flows parallel to the river Lech at only a few km distance. Towns along the Friedberger Ach include Weil, Prittriching, Mering, Friedberg, Rehling, Thierhaupten and Rain. After Rain, the Friedberger Ach flows east, parallel to the Danube, and joins the Danube near Oberhausen.