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.
Traisen (river)
The Traisen is formed from the rivers "Türnitzer Traisen" and "Unrechttraisen". Its total length, including the "Türnitzer Traisen", is . It is a tributary of the Danube in the Lower Austrian region of Mostviertel. Its two sources begin near St. Aegyd am Neuwalde and Türnitz respectively. After meeting, they flow through the municipalities of Türnitz, Lilienfeld, Traisen, Wilhelmsburg, and St. Pölten, before meeting the Danube at Traismauer. In the course of building the Danube Factory Altenwörth, the mouth of the Traisen was relocated to Altenwörth in the municipality of Kirchberg am Wagram.