Llullaillaco Volcano

The summit of South America’s Llullaillaco Volcano has an elevation of 22,110 feet above sea level, making it the highest historically active volcano in the world. The current stratovolcano--a cone-shaped volcano built from successive layers of thick lava flows and eruption products like ash and rock fragments--is built on top of an older stratovolcano. The last explosive eruption of the volcano, based on historical records, occurred in 1877.

Image credit: NASA