Cerro Rico de Potosi Silver Mine

POTOSI, BOLIVIA - MAY 25: The Cerro Rico de Potosí mine is one of the largest silver mines in Bolivia and in the world. The mine is located in the south of the country in Potosí. The mine has estimated reserves of 1.76 billion oz of silver and 540 million tonnes of ore grading 0.17% tin. it has been continuously mined for 472 years since the Spanish New World era. In 2014, UNESCO added Cerro Rico and Potosí to its list of endangered sites, owing to "uncontrolled mining operations" that risk "degrading the site". (Photo by Giles Clarke/Getty Images)