The Andes are the longest above-water mountain range on Earth, extending for about 7,000 kilometres along western South America.
The range follows the Pacific edge of the continent through seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina. It formed mainly through the subduction of the Nazca Plate beneath the South American Plate, a process that continues to produce earthquakes and volcanic activity.
The Andes contain a remarkable variety of environments, from tropical cloud forests to high deserts and glaciated peaks. Their highest summit is Aconcagua in Argentina, which rises to 6,961 metres. The Andes are sometimes described simply as the longest mountain range in the world, but that wording can be misleading because the Mid-Ocean Ridge is longer if underwater ridges are included. The usual above-water comparison identifies the Andes as the longest continental range.