Pinnacles of sandstone rise through the orange dunes of the Karnasai Valley, a few kilometers from Chad’s border with Libya. The orange sand is formed by the erosion of Nubian Sandstone, which itself was formed from ancient sand dunes millions of years ago. Thus the sand is being recycled, from dune to rock to sand and back to dune again. Strong Harmattan winds sandblast the base of the sandstone pinnacles, and beautiful wind pits around their bases. This is one of the most remote parts of the Sahara. Except for one or two families of goat herders who come here once a year, it is uninhabited and otherworldly.