From OpenwaterpediaDanube River is a river in Central Europe, the continent's second longest after the Volga River.
Classified as an international waterway, it originates in the town of Donaueschingen in the Black Forest of Germany at the confluence of the rivers Brigach and Breg. The Danube then flows southeast for 2,872 km (1,785 mi), passing through four Central and Eastern European capitals before emptying into the Black Sea via the Danube Delta in Romania and Ukraine.
Known to history as one of the long-standing frontiers of the Roman Empire, the river passes through or acts as part of the borders of ten countries. Its drainage basin is shared by Romania (28.9%), Hungary (11.7%), Austria (10.3%), Serbia (10.3%), Germany (7.5%), Slovakia (5.8%), Bulgaria (5.2%), Croatia (4.5%), Ukraine (3.8%), and Moldova (1.6%).
Long Distance Swim
Guinness World Records approved the July 2001 swim by Martin Strel down the Danube River when the Slovenian swimmer swam 504.5 km (313 miles) in 84 hours 10 minutes as the world's longest non-stop swim.