The stronghold of Mont-Dauphin in the Hautes-Alpes department occupies 143 acres (58 ha) of a rocky plateau rising between 2,946 and 3,444 ft (898 and 1,050 m) above sea level. Its designer, the Marquis de Vauban, took advantage of the natural defenses of the spur-shaped site by fortifying with a bastioned front only the part connected to the mountain on the side of the village of Eygliers. Behind a military structure, the stronghold housed at the beginning of the 18th century a true garrison town that allowed the two thousand or so soldiers who guarded it to be integrated into civilian life and thus limited the desertions. The population's water supply was provided by the nearby sources of Loubatière and Champs-Chignion.