The Andes are the longest mountain range on land, extending along the western edge of South America for about 7,000 kilometres. They pass through seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina.
The range formed mainly through the subduction of the Nazca Plate beneath the South American Plate. This ongoing tectonic process produces earthquakes, volcanoes, uplift, and deep valleys across the region.
Aconcagua, in Argentina, is the highest peak of the Andes and the highest mountain outside Asia. The Andes are sometimes confused with the Mid-Ocean Ridge, which is longer overall but lies mostly beneath the oceans. The Andes also strongly influence South American climate, including the extreme dryness of the Atacama Desert.