Aracar is a large conical stratovolcano in northwestern Argentina, just east of the Chilean border. It has a main summit crater about 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 , it covers a surface area of and has a volume of . The only observed volcanic activity was a possible steam or ash plume on March 28, 1993 seen from the village of Tolar Grande about southeast of the volcano, but with no evidence of deformation of the volcano from satellite observations. Inca archeological sites are found on the volcano.