Blaye, France

A worthwhile side trip between Cognac and Bordeaux is the small Unesco World Heritage-listed city of Blaye on the right bank of the Gironde river. The town’s imposing citadel was built by François Ferry, under the supervision of master citadel designer Vauban, in 1685, to protect the Gironde and the gates of Bordeaux.
Military significance aside, the town is known for its wines. The tourist office organises guided tours of the town, including boat tours revealing the strength of the fortifications from the point of view of a water-borne attacker.