The Granus Tower is one of the oldest surviving structures in the city. Its lower floors date back to the time of Charlemagne and reveal just how massive and functional early medieval architecture was. The tower stood as part of the Imperial Palace and marked a place where power and everyday life were closely intertwined. Later additions from the 14th century altered its appearance without obscuring its original character. Looking at the rough quarry stone masonry creates a quiet connection to an era whose traces have become rarer in Aachen.