The Mines of Potosí, Bolivia
Why it's controversial: The main attraction in Potosí is a trip into the cooperative silver mines adjacent to this high-altitude city in southern Bolivia. However, critics argue that this type of tourism is nothing more than a voyeuristic look at the miserable working conditions of poor men (and children) with little alternative in life.
Instead go to: The Atacama Desert of Chile, just across the border, where you can visit the Unesco World Heritage Sites of Humberstone and Santa Laura. Formerly service villages for saltpeter mines, they're now ghost towns that offer a remarkable story of the 20th century mining communities who etched out an existence in one of the most hostile environments on earth.