The longest continental mountain range in the world is the Andes. This immense mountain system follows the western edge of South America for roughly 7,000 to 8,900 kilometres, depending on where its boundaries are defined.
The Andes extend through seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina. They are not a single narrow ridge but a complex system of parallel ranges, high plateaus, valleys and volcanic zones. The Altiplano, a vast high plateau in Bolivia and Peru, is one of the range’s defining landscapes.
The Andes formed primarily through the subduction of the Nazca Plate beneath the South American Plate. That ongoing tectonic collision drives earthquakes, volcanic activity and continuing uplift. It also produced the range’s highest summit, Aconcagua in Argentina, which rises to about 6,962 metres.
The Himalayas contain the world’s highest mountains, including Everest, but they are shorter as a continuous continental range. The Rocky Mountains and Alps are also famous ranges, yet neither matches the Andes in total continental length. If submarine ranges are included, the global mid-ocean ridge system is much longer, but it is not normally meant by this quiz question.