Until 1909, Chile had something very special: large deposits of sodium nitrate. Also known as "white gold" or "Chile saltpeter," sodium nitrate is used in the production of fertilizer and explosives.
So valuable was this white gold that it caused Chile to go to war with its neighbors in 1879. In the oft-forgotten War of the Pacific or "saltpeter war," Chile, Peru and Bolivia all fought over territory containing the minerals with Chile gaining much of the disputed land.
At the turn of the century, the Saltpeter Works of Humbert and Santa Laura were both busy trying to extract as much of this Saltpeter as possible. Hundreds of buildings were built and whole communities of workers from South America, Europe and Asian formed around these towns. In the words of UNESCO they became a "distinct urban community with its own language, organization, customs, and creative expressions, as well as displaying technical entrepreneurship."
But something was coming that would change this all. In 1909 two German scientists, Fritz Haber and Carl Bosch figured out how to chemically fix nitrogen, that is, how to make this white gold on an industrial level. It was disastrous for the Saltpeter towns, and despite efforts to compete, by 1960 they were totally abandoned.
Today the towns' ghostly remains stand as rusting ruins in the inhospitable Atacama desert. In 2005 UNESCO declared them a World Heritage Site.
Other abandoned mining towns: