Located at the eastside of the historic Aachen town-hall the Granus-tower is showing an almost quadratic ground floor. As part of my work for the chair of monument-preservation I had the task to generate some photogrammatric pictures of the tower in scale 1:20. The results should support the historical research focussing the karolingian walls, done by Dr. Judith Ley working for the institute of building history and preservation of the RWTH Aachen. For making the shown photogrammetric images 502 single pictures were used in total. They were done with the help of an extreme, but distortion-free objective (17 mm) from a temporary scaffold in front of the tower. This was erected to renovate the tower’s plumb roof. The needed measure-points were surveyed by Marc Wietheger, who is belonging to the research-team as well.