Originally Posted by
Keith_M
A popular misconception about Vienna is that the river it was built on is the Danube. In actual fact, it was built on the river Wien, a tributary of the Danube. Wien is also the name of the city in German. The boundary of the city only reached the Danube in the nineteenth century.
Talking of the Danube...
If you're ever in Vienna and want to visit the Danube, make sure you specify which one when asking for directions, because there's (technically) three of them:
In the sixteenth century, the Danube was still quite far away from the city, so a canal was built (Donaukanal) to allow ships to offload next to the old walls. The water enters the canal unimpeded from the upstream Danube (Northwest) and rejoins it downstream (South-East), and is technically now a free flowing river in it's own right.
In the 19th century, the city of Vienna then decided to straighten the main part of the river. They built a long, straight ditch between the ends of a large curve of the river, then knocked down either end and let the river flood through. They then blocked up the original river curve, which is now a long narrow lake called the Alte Donau (Old Danube), which is much further away from the city centre... Incidentally, this was completed in 1875
Ergo, Vienna has three River Danubes.