Forty-eight kilometers east of the city of Iquique in the Atacama Desert in northern Chile, lies the remains of two large saltpeter works. Between the late 19th century and early 20th century, thousands of workers drawn from Chile, Peru and Bolivia lived and worked in the hostile environment of one of the driest deserts on Earth extracting and processing sodium nitrate, also known as saltpeter, which was used to produce fertilizers and, historically, gunpowder.

These deposits were exploited by Bolivia, Chile and Peru since the 1840s. A struggle between these countries to control the nitrate-rich region eventually led to the War of the Pacific (1879–1883), also known as the Saltpeter War, in which Chile defeated Peru and Bolivia, and gained a significant amount of land from both countries. These acquisition enabled Chile to practically monopolize the production of natural nitrate. By the 1890s Chile was supplying almost 80% of the nitrogen used in the world.

Photo credit: Carlos Varela/Flickr