Situated at the confluence of five river valleys, Briançon was highly vulnerable to attack by France's Alpine arch-rival of the 17th century, the Duchy of Savoy. After an especially damaging raid in 1692, vast effort was expended on constructing hilltop fortresses to defend the remote town, under the instructions of master military planner Vauban. These marvels of engineering, along with a dozen other Vauban sites in France, were given Unesco World Heritage status in 2008.
Perched atop a rocky crag high above the Cité Vauban, the Fort du Château (1326m) can be visited on foot from late April to November. Across the 55m-high Pont d’Asfeld (erected 1731), a graceful stone bridge over the Durance River, Fort des Trois Têtes (1435m) can be seen on a walking tour in the warm season. The Fort des Salettes (1400m) is accessible on foot or on guided snowshoe tours; ask at the Service du Patrimoine, inside the Cité Vauban's main gate.
