Pular is a massive stratovolcano located in the Antofagasta Region of northern Chile, about 15 km west of the border with Argentina, which in this area is a straight line between the summits of Socompa volcano and Cerro del Rincón. Pular, along with Cerro Pajonales, forms a high volcanic ridge, which runs in a generally north-east to south-west direction for 12 km (7 mi). Southward, following the same direction as the ridge, lies Socompa volcano. The ridge's crest forms a drainage divide between Salar de Atacama basin and Salar de Pular basin. This latter is a bowl-shaped basin enclosed on the east by Aracar volcano.

Aracar is a large conical stratovolcano in northwestern Argentina, just east of the Chilean border. It has a main summit crater about 1–1.5 kilometres (0.6–0.9 mi) in diameter which sometimes contains crater lakes, and a secondary crater. The volcano has formed, starting during the Pliocene, on top of a lava platform and an older basement. Constructed on a base with an altitude of 4,100 metres (13,500 ft), it covers a surface area of 192.4 square kilometres (74.3 sq mi) and has a volume of 148 cubic kilometres (36 cu mi). The only observed volcanic activity was a possible steam or ash plume on March 28, 1993, seen from the village of Tolar Grande about 50 km (31 mi) southeast of the volcano, but with no evidence of deformation of the volcano from satellite observations. Inca archeological sites are found on the volcano.