Gap is the prefecture of the Hautes-Alpes department in the Provence-Alpes-Côte d'Azur region in Southeastern France. In 2019, the commune had a population of 40,631, making it the most populated city in Hautes-Alpes. At a height of 750 metres above sea level, to the south of the Écrins Massif, it is also France's highest prefecture.