Already naturally protected by its overhanging position, the stronghold of Mont-Dauphin is also protected by an enclosure made up of several fronts - the Eygliers front to the northeast, the Guil front to the southeast, the Embrun front to the southwest, and the front of the Durance to the west - which cover the gates of Briançon and Embrun. Each front with masonry walls of rubble and freestone follows an architecture specifically adapted to the topography of its location. On the Eygliers front stand two identical and asymmetrical bastioned walls with escarpments preceded by ditches; the Guil front has batteries; the Embrun front houses casemates. As for the walls of the front of the Durance, they crown the cliffs that dominate the river.