The sand dunes here can grow taller than a ten-storey building. Strong desert winds sculpt them into perfect curves and push them slowly across the land - a big dune can move several metres in a year, almost like a very slow river of sand.
Not all of Western Sahara is soft sand. Large areas are flat, stony gravel plains called regs. The gravel is smoothed flat by thousands of years of wind, and you can see for kilometres in every direction without a single tree blocking the view. On clear nights, the stars over these plains are breathtaking.
Desert temperatures swing wildly. During the day the sun can heat the sand until it burns to touch. At night the same desert can turn surprisingly chilly because there are no clouds to trap the warmth. Saharan people have learned exactly when to travel, rest, and seek shade.