Natural regions of Chile for reference purposes. These natural regions are ordered from north to south and reduced to five natural regions: Each has its own characteristic vegetation, fauna, climate, and, despite the omnipresence of both the Andes and the Pacific, its own distinct topography. Most of the region is covered by the Atacama Desert and has a dry arid climate. The coast range has peaks over 2000 m and ends in cliffs in the coast. There are large salt flats in the Intermediate depression and the Andes. Norte Grande has Chile's highest mountains including Ojos del Salado (6,891 m) but host also the
Llullaillaco Llullaillaco Llullaillaco () 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. Llullaillaco formed during two different phases in the Pleistocene-Holocene out of dacitic lava flows. The oldest rocks are about 1.5 million years old. About 150,000 years ago, the volcano's southeastern flank collapse, generating a debris avalanche that reached