Llullaillaco (Spanish pronunciation: [ʎuʎajˈʎako]) is a dormant stratovolcano at the border of Argentina (Salta Province) and Chile (Antofagasta Region). It lies in the Puna de Atacama, a region of tall volcanic peaks on a high plateau close to the Atacama Desert, one of the driest places in the world. It is the second highest active volcano in the world after Ojos del Salado.