The silver mine of Potosi was a pillar of the Spanish Empire, with catastrophic repercussions on the indigenous population: an estimated eight million Inca slaves died in the process. In the 17th century Potosi was one of the world’s wealthiest city, now it is basically a dump, except for a few well-preserved colonial buildings (under restoration by UNESCO) and a museum. What remains of Potosí's past wealth is observable only in the expression ""un potosí"", used to describe someone very rich.

The mine is still open, and if you are in good physical conditions, I highly recommend a visit: it was one of the most physically-challenging experiences of my year-long overland South American trip (and heck that trip was tiring in itself)!