Vauban's Fortresses: Lille to Briançon

Lille was taken from Spain in August 1667, and Louis XIV immediately ordered a fortress. Vauban's plans were the ones the king chose; work began in 1668 and the citadel was operational by 1671. The idea was simple and deadly: no wall can be approached by an enemy without being under fire from a nearby wall. It is called the "Queen of Citadels" and was the matrix for most of Vauban's later citadels.

Perched on Mount Saint-Etienne, in the neck of a loop of the river Doubs, the citadel covers 11 hectares and is considered one of Vauban's finest works. Julius Caesar had already noticed the site's strategic value in 58 BC. Vauban came back 17 times between 1674 and 1703 to oversee the building. It cost so much that, so the story goes, the king asked him whether he was building the walls of gold.

After the Treaty of the Pyrenees of 1659, Louis XIV wanted to secure the border with Spain, and in 1679 Vauban designed this stronghold. The citadel has a square plan with four bastions at the corners, dry moats and barracks built into the ramparts. The Saint-Louis gate, topped by a bell tower and a clock, opens straight onto the town, whose walls have 25 sentry posts.

The island of Ré had been fortified under Cardinal Richelieu as a counterweight to Protestant La Rochelle, and in 1627 an English force under the Duke of Buckingham was forced to withdraw. Vauban inspected the town in 1685 and proposed additions. The result was an enclosed town able to house the whole island's population through a long siege. The citadel, ringed by six bastions and a dry moat, was built in only 40 days.

Built in 1692 by Vauban on the head of a plateau, Mont-Dauphin follows an orthogonal plan, with straight streets inside the walls. The fortress holds barracks such as the Rochambeau barracks, an unfinished church and the Saint-Louis parish church. Today the former officers' pavilion offers 16 lodgings to tourists, so you can sleep inside the walls.

Visitor guidance: The officers' pavilion takes guests in 16 lodgings.

Built from scratch between 1698 and 1703 near the border with Germany, Neuf-Brisach is one of Vauban's last works and the only example of his third system, with a double town wall. The streets form a square grid inside an octagonal fortification. Vauban died in 1707 and Louis de Cormontaigne completed it. The town was bombarded from 2 to 10 November 1870, and UNESCO listed it in 2008.

Vauban visited Briançon twice, in 1692 and 1700, and rebuilt the medieval town wall between 1692 and 1700. The bridge came later, under his successor the marquis d'Asfeld: a masonry bridge of a single arch across the Durance, rising 56 m above the river. Work resumed on 20 April 1730 with the first stone. Together with the wall, the Redoute des Salettes and the forts it is part of the UNESCO listing.