South of La Paz, the southern Altiplano – the high plateau between the eastern and western chains of the Andes – stretches 800km to the Chilean and Argentine borders. It was formed millions of years ago by sediments washed down from the mountains into the deep valley between the cordilleras Oriental and Occidental as they were pushed up from the sea bed. Set at an average altitude of around 3700m, this starkly beautiful, barren landscape has arid steppes stretching to the horizon, where snowcapped mountains shimmer under deep-blue skies. With scant rainfall and infertile soils it supports only a sparse rural population. Since the Spanish conquest, the Altiplano’s prime importance has lain in its rich mineral deposits; its silver deposits have largely run out but tin and lithium deposits remain.
The unavoidable transport nexus of the region is the rather grim tin-mining city of Oruro, 230km south of La Paz. West of Oruro, a chain of snowcapped volcanic peaks – the Cordillera Occidental – marks the border with Chile and the edge of the Altiplano. One of these peaks, Volcán Sajama, is Bolivia’s tallest mountain and centre of a national park. Some 310km further southeast of Oruro is the legendary silver-mining city of Potosí, marooned at 4100m above sea level.
From Uyuni, 323km south of Oruro, you can venture into the dazzling white Salar de Uyuni, the world’s biggest salt lake and one of Bolivia’s best-known attractions. Beyond the Salar in far southwestern Bolivia is the Reserva de Fauna Andina Eduardo Avaroa, a remote region of high-altitude deserts, surreal rock formations, volcanic peaks and mineral-stained lakes that supports great populations of flamingos and vicuñas. Southeast of Uyuni the Altiplano changes character. The town of Tupiza is surrounded by arid red mountains and cactus-strewn badlands. Different again is Tarija, in the far south, a welcoming city in a fertile valley known as the Andalucia of Bolivia.
The whole region is bitterly cold at night, particularly from May to July. Even during the day temperatures can fall sharply, though you’ll also need to protect yourself from the fierce, high-altitude sunshine.