The Cerro Rico, or Rich Mountain, looms over Potosí, Bolivia, the highest city in the world at 14,000 feet above sea level. In 1545, Spanish conquistadors discovered what was to become the world's largest and richest silver mine here in one of the most remote places on earth.
The staggering riches, mined with forced labor from this fabled and forgotten mountain, financed the Spanish conquest of the Americas. Despite its history of extraordinary wealth, Potosi sits in what is now the poorest province in the poorest country in South America.
Watch the story tonight on "Nightline" at 11:35 p.m. ET (Jeffrey Kofman/ABC News)