The city of Aachen (pronounced "AH-ken") in western Germany has a population of about 257,000 people. Aachen is known to French speakers as Aix-la-Chapelle and to Italians as Aquisgrana (reflecting its original Latin name). Aachen was the site of an ancient sacred hot spring, but is best known for its later association with Emperor Charlemagne.

The main attraction of Aachen is the well-preserved Aachen Cathedral, commissioned by Charlemagne in 786 AD. The unique cathedral has a round nave and notable Byzantine influences, and its treasury includes the coronation throne of the Holy Roman Emperors. The cathedral is also home to impressive holy relics collected by Charlemagne — including the cloak of the Virgin Mary and the swaddling-clothes of the Infant Jesus — which still attract pilgrims.