The Atacama Desert is a plateau in South America, covering a 600-mile (1,000 km) strip of land on the Pacific coast, west of the Andes mountains. It is, according to NASA, National Geographic and many other publications, the driest desert in the world. The Atacama occupies 40,600 square miles (105,000 km2) in northern Chile, composed mostly of salt basins (salares), sand, and felsic lava flows towards the Andes.