Coordinates: 21°45′S 67°50′W / 21.750°S 67.833°W Pastos Grandes is the name of a caldera and its crater lake in Bolivia. The caldera is part of the Altiplano-Puna volcanic complex, a large ignimbrite province that is part of the Central Volcanic Zone of the Andes. Pastos Grandes has erupted a number of ignimbrites through its history, some of which exceeded a volume of 1,000 cubic kilometres (240 cu mi). After the ignimbrite phase, the lava domes of the Cerro Chascon-Runtu Jarita complex were erupted close to the caldera and along faults.
The caldera is the site of a few lakes, some of which are fed by hot springs. A number of minerals, including lithium, are dissolved in the lakes.
Pastos Grandes lies in the Sud Lipez Region of Bolivia. Geographically the area is part of the Altiplano, a high plateau bordered by the Cordillera Occidental and the Cordillera Oriental. The Altiplano contains two large salt pans, the Salar de Uyuni and Salar de Coipasa. The specific area of Pastos Grandes is remote and poorly accessible, the existence of the caldera was first established by satellite imagery.