Nevado Ojos del Salado is a stratovolcano in the Andes on the Argentina–Chile border and the highest active volcano in the world at 6,893 m (22,615 ft). It is also the second highest mountain in the Western Hemisphere and Southern Hemisphere and the highest in Chile. Despite the generally dry conditions, there is a permanent crater lake about 100 m (330 ft) in diameter at an elevation of 6,390 m (20,960 ft) on the eastern side of the mountain. This is most likely the highest lake of any kind in the world.

The ascent of Ojos del Salado is mostly a hike except for the final section to the summit which is a difficult scramble that may require ropes. The first ascent was made in 1937 by Jan Alfred Szczepański and Justyn Wojsznis, members of a Polish expedition in the Andes.