The Fort du Château dominates the city of Briançon in the Hautes-Alpes department from the top of its rock, described as naturally steep by Vauban. A medieval castle at the time of the Dauphins, this work then described as a wall of 787 ft (240 m) in perimeter with four towers, a large square keep, accommodations, and a chapel underwent many developments in the 17th and 19th centuries. In its current configuration, only the powder magazine designed by Vauban has been preserved and registered on the UNESCO World Heritage List.