Danube
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 about , passing through four capital cities (Vienna, Bratislava, Budapest and Belgrade) before emptying into the Black Sea via the Danube Delta in Romania and Ukraine.
Upper Danube Nature Park
The Upper Danube Nature Park (German: "Naturpark Obere Donau"), founded in 1980, is located in the south of Baden-Württemberg in Germany and encloses primarily the districts of Tuttlingen and Sigmaringen. It encompassed initially 860 km that were increased by about 500 km in 2005. The headquarters of the nature reserve association is at Beuron. The highest proportion of the nature park is taken up by the Heuberg, the south-western plateau of the Swabian Alb, and is punctuated by the Danube.