The fortified city forms part of the 14 major Vauban sites in France, just like the Arras and Belle-Ile-en-Mer Citadels, the fortifications of Mont-Dauphin or the citadel and fort in Besançon.
Vauban's plan for Briançon, at the intersection of the five valleys in a star shape configuration, consists in occupying the heights overlooking the town with forts. The projects designed by him would only be built from 1713
Working on the principal that the attackers must necessarily be Christian, Vauban placed his collegiate church on the most exposed bastion of the fortress!
The project encircled the town with a vertical staggered system of ramparts, backed up by the protection of the forts placed on the surrounding dominant points around the town in order to ensure that the town was entirely impregnable.
Two visible channels cross Vauban's fortified Medieval city: the Grande (Large) and Petite Gargouille (Small Gargoyle). The houses make up a picturesque and colourful mosaic.