At the edge of an oasis almost engulfed by the dunes, where the rare caravan still passes, is a desert landscape punctured by holes.
The salt pans of Kalala, near Bilma in northeastern Niger, were once an essential stop for traders with their swaying lines of camels.
Salt-digging, carried on from generation to generation, was a thriving business, involving a commodity so precious that it was bought and sold across the Sahara and beyond.