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.
Ulm
Ulm lies at the point where the rivers Blau and Iller join the Danube, at an altitude of above sea level. Most parts of the city, including the old town, are situated on the left bank of the Danube; only the districts of Wiblingen, Gögglingen, Donaustetten and Unterweiler lie on the right bank. Across from the old town, on the other side of the river, lies the twin city of Neu-Ulm in the state of Bavaria, smaller than Ulm and, until 1810, a part of it (population c. 50,000).