Geographical terrains of South America: a quick overview

There are 3 main geographic terrains in South America, although the continent is home to a vast diversity of biomes, including extreme environments such as the Atacama Desert in northern Chile (the driest place in the word) and Aconcagua, Argentina, the tallest mountain outside of Asia (9,962 meters). These three main terrains are mountains and highlands, river basins and coastal plains.

Mountains and Highlands

The primary mountains of the continent are the Andes, the longest mountain range in the world at 8,850km. These mountains stretch along the entire western side of South America, from the tip, top to the very bottom. The highest peak in this mountain range is Aconcagua, which is the highest peak in the world outside of Asia. Among Aconcagua peak are hundreds of others, many of which are volcanic.

Other than the Andes, South America has two other major highland areas. The Brazilian highlands are located south of the Amazon River in Brazil, while the Guiana Highlands are situated between the Amazon and Orinoco Rivers, their forested plateau extending from southern Venezuela through Guyana and French Guiana to northern Brazil.

River Basins

The three most important river basins in South America are the Amazon, the Orinoco, and the Paraguay/Paraná.

The Amazon basin, extending almost 7 million square kilometers, is the largest watershed in the world. This shouldn’t be a surprise, as the Amazon River is the widest river in the world. This basin is fed by tributaries from the glaciers in the Andes that trickle down into the dense rainforest that spans the basin. Every single second, the Amazon River empties 209,000 cubic meters of freshwater into the Atlantic!

The Orinoco River, north of the amazon, originates in the Guiana Highlands and ends at the Atlantic Ocean in Venezuela, moving in an arc shape. The biome, or community of organisms in a specific area and climate, in this basin is not a rainforest like in the Amazon, but is a grassland and low-lying swamp ecosystem. It is here that you will find the famed piranhas and electric eels!

The Paraguay/Paraná basin is 2.8 square km and covers most of southeastern Brazil, Bolivia, Paraguay, and northern Argentina. The Paraná River and the Uruguay River together empty into the Rio de la Plata estuary between Uruguay and Argentina, a highly populated area. The capitals of both countries, Montevideo and Buenos Aires, sit on opposite edges of the estuary. The famous Iguazú Falls, the largest series of waterfalls in the world extending 2.7 km, are part of the Paraná River. This river basin supplies water to the Pampas biome, which has rich soil and is the most important grazing and cropland on the continent.

Coastal Plains

A coastal plain is a flat, low-lying area next to an ocean coast. In South America, there are coastal plains on the northeastern coast of Brazil, on the Atlantic Ocean, and along the Pacific coast to the west of Peru and Chile. Part of the western coastal plain is the Atacama Desert of northern Chile, which is the driest location in the world (certain places have experienced no rainfall in recorded history!)

Trinidad and Tobago, Aruba, Curaçao, and the Caribbean Netherlands (Bonaire, Saint Eustatius, Saba) are off the coast of Venezuela in the Caribbean, while the Falkland Islands, which have disputed ownership (Argentina claims this archipelago, but it is legally a British Overseas Territory) are on the eastern coast of Argentina in the Atlantic Ocean. The South Sandwich Islands, also British Territory, are associated with the continent as well. Finally, French Guiana on mainland South America is considered part of France, and thus the EU, despite its location.

Other notable terrains are the vast Andes Mountains on the eastern coast and the dramatic archipelagos and islands surrounding the continent. Trekking and snow sports are very popular in the Andes, where there is consistent snow at the peaks, and gorgeous geological formations along this volcanic orogeny. The many islands surrounding the continent, from tropical paradises to Antarctic wonderlands, are home to incredibly unique ecosystems. Endemic species and complex species interactions remain undamaged by humans in certain places, such as the Galapagos and remote Patagonian islands in the south.