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.
Danu (Irish goddess)
The etymology of the name has been a matter of much debate since the 19th century, with some earlier scholars favoring a link with the Vedic water goddess Danu, whose name is derived from the Proto-Indo-European root "*dʰenh₂-" "to run, to flow", which may also lie behind the ancient name for the river Danube, "Danuuius" – perhaps of Celtic origin, though it is also possible that it is an early Scythian loanword in Celtic.