Pastos Grandes Caldera or Cerro Pastos Grandes (a resurgent centre) is an old caldera in the Potosí Department, Bolivia, which belongs to the Altiplano-Puna Volcanic Complex. Lagunas Pastos Grandes, Khara and Cachi may be remnants of a greater caldera lake. Size of the caldera: 50 km x 40 km. A large (VEI 7) eruption c.