Roughly 3,750 metres above sea level, between the Western and Eastern cordilleras of the central Andes, lies the Altiplano, or Collao: the most extensive high plateau on Earth outside Tibet. Most of it is in western Bolivia, with its northern end in southern Peru, its southwestern fringe in Chile and a tip in northwest Argentina. It is an endorheic basin, a cold, windy high plain whose rivers never reach the sea, ending instead in Lake Titicaca (3,812 m), the former Lake Poopó and salt flats such as the Salar de Uyuni. Lake Titicaca has been a Ramsar wetland since 26 August 1998, and Bolivia’s Sajama National Park, first protected in 1939, adjoins Chile’s Lauca National Park on its western rim. Above all, the Altiplano is a lived-in landscape: home to Aymara and Quechua farmers, Uru lake dwellers, herders, miners and some of the highest large cities in the world.
El Alto, Juliaca, Oruro and Puno: Cities Above 3,700 Metres
The plateau’s largest city did not exist a century and a half ago. El Alto, on the rim of the canyon that holds La Paz, was almost empty until 1903, when railways from Lake Titicaca and Arica reached the canyon edge and railway workers settled beside the yards. An air force airfield followed in 1925, and growth took off in the 1950s, once the settlement was connected to the La Paz water supply and migration from the countryside accelerated after the rural reform of 1952. El Alto was separated from La Paz in March 1985, incorporated as a city in 1987, and was estimated at 943,558 people in 2020, making it Bolivia’s second-largest city. At an average elevation of about 4,000 m it is also the highest major city in the world, and a cable-car network now links it directly to central La Paz. Its rapid growth has left outlying districts short of piped water, sewers and paved roads.
On the Peruvian side, Juliaca, 3,825 m up on the Collao plain about 45 km northwest of Lake Titicaca, is the largest city of the Puno Region, with 276,110 people in 2017. It is the region’s main trading centre, long known for knitting socks and sweaters from local wool and nicknamed the Windy City for the gusts that sweep the plateau. Puno, founded in 1668, had 135,288 people in 2017 and is Titicaca’s major Peruvian port town. Its economy rests on agriculture and on llamas and alpacas grazing the surrounding plains, alongside a large informal trade in goods brought across the border from Bolivia.
Oruro, at 3,709 m roughly halfway between La Paz and Sucre, is the plateau’s mining city. With 264,683 people in 2012 it is Bolivia’s fifth-largest city, and its fortunes have risen and fallen with tin, tungsten, silver and copper prices. Long before the Spanish arrived, the Uru people were prominent around Oruro, and the Incas later governed the region of Kollasuyo from nearby Paria.
Reed Islands, Trout and a Lost Lake: Fishing Communities of Titicaca and Poopó
Lake Titicaca, straddling the border between Peru’s Puno Region and Bolivia’s La Paz Department, covers about 8,372 km², the largest lake in South America by both area and volume. It has 41 islands, several densely populated, and each has its own way of making a living. About 1,200 Uros lived in 2011 on an archipelago of some 60 floating islands near Puno, built from the buoyant totora sedge. The base of each island is a one-to-two-metre layer of matted totora roots called khili, cut in blocks of about 4 by 10 m, tied together, anchored to eucalyptus poles and topped with fresh reeds every two weeks to three months, faster in the rainy season. An island lasts about 25 years before it is replaced. The Uros once lived about 14 km out on the lake but moved closer to shore after a major storm in 1986, and ferrying visitors from Puno now supplements the fishing and hunting they have long lived on.
The natural islands are farming communities. Taquile, 45 km offshore from Puno, has about 2,200 Quechua-speaking residents. They farm terraced potato fields divided into six rotating sectors and run a community-controlled tourism model of homestays and local guides for the roughly 40,000 visitors a year. Amantani supports 3,557 people (2017 estimate) on 9.28 km², and on Bolivia’s Isla del Sol about 800 families farm, fish and host visitors. The fishery itself has been transformed: introduced rainbow trout and Argentine silverside compete with the lake’s native Orestias killifish, of which 23 species live nowhere else, and the Titicaca orestias has not been seen since 1938. Since 2000 the lake level has been falling, dropping 81 cm between April and November 2009 alone, and a 2011 United Nations report found high concentrations of cadmium, arsenic and lead in parts of the lake.
Farther south, the people of Lake Poopó lost their lake altogether. Poopó, in Oruro Department at about 3,700 m, was Bolivia’s second-largest lake, with a permanent area of about 1,000 km² that swelled to 3,500 km² in 1986. Fed mostly by the Desaguadero River flowing out of Titicaca, with a mean depth of less than 3 m, it was named a Ramsar site in 2002. By December 2015 it had dried up completely, and the Bolivian government declared the area a disaster zone on 20 January 2016. Rising temperatures since 1995 had tripled evaporation, while mining and irrigation drew off water, and by 2017 the fishing on which nearby communities depended had all but disappeared.
Quinoa and Llama Herds: Farming at the Altitude Limit
Farming on the Altiplano works within hard limits. Mean annual temperatures range from about 3 °C near the Western Cordillera to 12 °C beside Lake Titicaca, nights can fall to −20 °C, and rainfall drops from more than 800 mm a year around the lake to less than 200 mm in the southwest. Rain is concentrated between December and March. Titicaca’s great mass of water softens the cold along its shores, which is why settlement and farming cluster there.
Quinoa is the plateau’s gift to the world. It was domesticated around Lake Titicaca and eaten by people there 3,000–4,000 years ago, and most cultivars grow between 2,500 and 4,000 m. In 2023 world production was 112,251 tonnes, with Peru producing 62 percent and Bolivia 37 percent. The premium Quinoa Real grows in Bolivia’s Intersalar region between the Uyuni and Coipasa salt flats, in high salinity, intense ultraviolet light and drought. Export demand tripled prices between 2006 and 2013, with an average of US$3,115 a tonne in 2011, before production spread to more than 70 countries and prices collapsed from 2015, hitting Andean smallholders hard.
Where crops struggle, animals take over. Llama and vicuña herding remain among the plateau’s main economic activities, and on islands such as Amantani the hand-worked terraces planted with wheat, quinoa and potatoes share the slopes with grazing sheep. The more humid northeast of the plateau suits this mix of small fields and pasture, while the arid southwest, with its salt flats, is left largely to herds, salt and mines.
Salt and Lithium on the Salar de Uyuni
In the far south the plateau’s economy turns to minerals. The Salar de Uyuni, in Potosí Department at 3,656 m, is the largest salt flat in the world at about 10,582 km², the dried floor of a chain of Pleistocene lakes now covered by a salt crust that varies in height by less than a metre across its whole surface. It holds an estimated 10 billion tonnes of salt, of which less than 25,000 tonnes is extracted each year, all of it by miners belonging to the cooperative of the village of Colchani. The flat doubles as a road across the Bolivian Altiplano when it is dry, and as a tourist destination when a film of rainwater turns it into a mirror.
Beneath the crust lies brine rich in lithium, at a concentration of about 0.3 percent. As of 2024 Bolivia held an estimated 23 million tonnes of lithium, about 22 percent of the world’s 105 million tonnes of known resources, most of it under the Salar. Extraction has been slow: foreign projects in the 1980s and 1990s met strong local opposition from residents who doubted the money would reach them, and impurities, wet seasons and altitude make the brine harder to process.
Tiwanaku, the Aymara and Sajama: The Plateau’s Long Human Record
Today’s communities stand on a very long record. Ancestors of the Aymara, who number about 2.3 million across Bolivia, Peru, Chile and Argentina, have a continuous genetic heritage in the highlands going back at least 8,750 years. About 70 km from La Paz, near Lake Titicaca, the city of Tiwanaku was founded around AD 110 and grew between about AD 375 and 700. At its height it covered roughly 4 km² and held 10,000 to 20,000 people around AD 800, fed by an agropastoral economy that included the raised fields known as suka kollus, rediscovered by excavations from 1978 into the 1990s that also linked the culture’s collapse to drought. Tiwanaku is now a UNESCO World Heritage Site.
On the western edge, Sajama National Park in Oruro Department shows how people and conservation overlap. Bolivia’s oldest national park, it was declared a nature reserve in 1939 to protect queñoa trees that were being cut for charcoal to supply Bolivian mines, and it rises from 4,200 m to the 6,542 m summit of Sajama, Bolivia’s highest mountain. About 300 Aymara families live in the park’s area of influence. Across the border, Chile’s Lauca National Park covers 1,379 km² of altiplano and volcanoes around Lake Chungará and the village of Parinacota with its colonial church.
For the lake at the centre of this story, see the guide to Lake Titicaca’s geography, and for the ruined city, the account of Tiwanaku in Bolivia; the plateau itself is one chapter of the much longer Andes mountain chain.