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.
EuroVelo
Running from Saint-Nazaire on the mouth of the River Loire along that river eastward through France, EV6 passes over the border to Switzerland to Lake Constance and then on to Tuttlingen in Germany, where it begins its way down the Danube following the (Danube Cycle Route). It follows that river, Europe's second longest, through Germany, Austria, Slovakia, Hungary, Serbia, Bulgaria and Romania to the river's mouth at the Danube Delta. It then continues southwards to end in Constanța, on the Black Sea.
EV7 runs from the North Cape to Malta, will whisk you from the Arctic Circle in Norway, the land of the midnight sun, to island hopping in the Mediterranean.