3 macedonboy - 2 years ago
As others have already mentioned, this tower was part of the old Roman fortifications. The city has certainly done a good conservation job as the tower is in remarkably good condition and many of the decorations such as geometric patterns that adorn the exterior are well preserved.
It doesn't appear to be possible to enter the tower, what you see from the outside is all you get. It's interesting, but well off the tourist circuit in Cologne. So I wouldn't go out of the way to see it.