The average width (east-and-west) is less than 160 kilometers (100 miles) but it extends from the Peruvian border 1000 kilometers (600 miles) south to the Bolivian Antiplano. The mountains nearest the ocean are the Pacific coastal range, with an average elevation of 800 meters (2500 feet). The Cordillera Domeyko, a range of foothills of the Andes Mountains, lies east.
The Atacama is inhabited, though sparsely populated. The Pan-American Highway runs through the Atacama, and in the center of the desert, at an altitude of some 2000 meters, is the village of San Pedro. Its church is recent, having been erected by the Spanish in 1577, but archeological evidence indicates that the San Pedro area was the center of a Paleolithic civilization that built rock fortresses on the steep mountains encircling the valley.