A nearly complete circuit of 13th-century walls surrounds the old town, and much of it can be walked from the top. The rampart walk takes about an hour at a leisurely pace, passing towers, gateways, and viewpoints along the way. The Jardin Anglais — a small terraced garden built on the site of the old priory cemetery — sits at the best vantage point, looking down the Rance valley to the viaduct and the port below.
Several towers are incorporated into the walls, including the Tour Sainte-Catherine and the Tour du Connétable. The most impressive section runs between the Château and the port side, where the ramparts stand at their original height.