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.