Cranes are an important part of the skyline of Vienna.
One might think they're standing there just for our pleasure to watch, but I suppose they're set up for some reason, and most of the times you'll find that these construction cranes actually do stand at a construction site:

By the way, a crane like this was felled yesterday by Emma, a crane standing on Südbahnhof, the most important railway station of the town. But this one obviously has survived, or else it would have been in the news.