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.
Rába
The Rába (; ; ) is a river in southeastern Austria and western Hungary and a right tributary of the Danube. Its source is in Austria, some kilometres east of Bruck an der Mur below Heubodenhöhe Hill. It flows through the Austrian states of Styria and Burgenland, and the Hungarian counties of Vas and Győr-Moson-Sopron. Its is long, of which about 100 km in Austria. It flows into a tributary of the Danube (Mosoni-Duna) in northwestern Hungary, in the city of Győr. Towns along the Rába include Gleisdorf, Feldbach (both in Austria), and Szentgotthárd and Körmend (in Hungary). In the early Cenozoic the river used to flow in the opposite direction, but tectonic uplift reversed this flow.