Considering the Balladins Superior de Metz in Metz?
A VT member wrote the following comment about visiting Metz:
The City Walls by Tom_Fields
Metz was once the most heavily fortified city in western Europe. Its extensive network of walls surrounded it, making it capable of withstanding a protracted siege. Today, little remains of the walls, which (like most medieval walls) were mostly pulled down to make way for urban development. Many streets in Europe follow the routes of the old city walls. But a sizable portion of the old walls still remain. Strolling around these walls gives on a "feel" for what the city was like once.
The most outstanding feature that survives today is the Porte des Allemands, or German Gate. It stand on the northeast side of the old city, facing Germany. Here is an excellent example of medieval military architecture. Touring the walls also affords the visitor a chance to get a little exercise; it's a pretty good hike.