View from Donauturn (Danube Tower) to the "Obere Alte Donau" (Upper Old Danube) and Floridsdorf.
The church you can see on the other side is the Saint Leopold's Church (Donaufelder Pfarrkirche St. Leopold) in Floridsdorf.
The "Alte Donau" (Old Danube) in Vienna is a dead end of a former river branch of the Danube, separated from the actual Danube by a dam. Since the Alte Donau has no direct connection to the main course of the river, it is a shallow lake that is popular as a recreational area. The Alte Donau is one of the very few attractions of the otherwise boring suburban district of Floridsdorf, the 21st district of Vienna. The Alte Donau is divided into two sections by the Kagraner Brücke, a bridge. The north-western part is called "Obere Alte Donau" (Upper Old Danube) and extends between the Floridsdorfer Brücke and the Kagraner Brücke. The south-eastern part is called "Untere Alte Donau" (Lower Old Danube) and extends to the Praterbrücke, where you also find the previously mentioned dam.