Bordered by the Lure chain, the Luberon, and the Durance and Cavalon valleys, the Forcalquier basin forms the heart of the eponymous region. At certain times in its history, it extended its influence to a larger area that included the Jabron valley and the two slopes of the Lure mountain. It is crossed diagonally by the Via Domitia that linked Italy to Spain in Roman times and served as a path for Christianization.