Aachen

French: Aix-la-Chapelle, Dutch: Aken,

city, North Rhine-Westphalia Land (state), western Germany. Its municipal boundaries coincide on the west with the frontiers of Belgium and The Netherlands. It was the favorite residence of the emperor Charlemagne, and it served as the principal coronation site of Holy Roman emperors and of German kings from the Middle Ages to the Reformation. The Palatine Chapel, a masterpiece of Carolingian architecture, is incorporated within Aachen Cathedral, which was added to UNESCO's World Heritage List in 1978.