The Atacama Desert is a 990 mi strip of land on the Pacific coast, west of the Andes Mountains. It is the driest non-polar desert in the world and the only true desert as it receives less precipitation than the polar deserts and is the largest fog desert in the world. Most of it consists of a stony terrain with salt lakes, sand and felsic lava that flows toward the Andes. In pre-Columbian and Colonial times it was a large flatland area known as Pampa del Tamarugal and was forested. Deforestation occurred to the voracious demands of silver, copper and saltpeter mining in the 18th and 19th centuries. The terrain has been compared to that of Mars. The reason to go is to see and marvel at the wonderful, larger than life pictographs and geoglyphs that are visible from the ground. They depict llamas, camels, eagles, condors and hunters. It is an amazing place filled with volcanoes, lava fields and undulating sand dunes making up the seemingly endless desert.