Dating back to the 13th century, this tower is one of the oldest structure in Bonn. It used to be a part of the city fortification. Interestingly, the tower had to be moved at the end of 19th century, due to increasing traffic. It now stands a few meters from its original location.
Wikipedia http://de.wikipedia.org/wiki/Sterntor_(Bonn)
Official website http://www.bonn-region.de/sightseeing-and-culture/sterntor-en.html
Address Vivatsgasse 8 53111 Bonn, Germany
Coordinates 50°44'6.926" N 7°5'54.716" E