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.
Podunavlje
Podunavlje (Serbian: Подунавље / "Podunavlje", ) is the name of the Danube river basin parts located in Serbia (Vojvodina, Belgrade and Eastern Serbia) and Croatia (Slavonia, Syrmia, and Baranja). Podunavlje is located on the southern edge of Pannonian Basin. In its wider meaning, the term is used in Serbian and Croatian as a description for the area around the entire flow of the river Danube.