Paths of Glory by Irvin S. Cobb

There is a corner of Rhenish Prussia that shoulders up against Holland and drives a nudging elbow deep into the ribs of Belgium; and right here, at the place where the three countries meet, stands Charlemagne's ancient city of Aix-la-Chapelle, called Aachen by the Germans.

To go from the middle of Aix-la-Chapelle to the Dutch boundary takes twenty minutes on a tram-car, and to go to the Belgian line requires an even hour in a horse-drawn vehicle, and considerably less than that presuming you go by automobile. So you see the toes of the town touch two foreign frontiers; and of all German cities it is the most westerly and, therefore, closest of all to the zone of action in the west of Europe.