Potosi is the highest city in the world and owes its existence to Cerro Rico, which is a legendary silver mine which produced fabulous wealth for the Spanish and untold misery for the mine working indigenous slaves. The silver is mostly played out but many cooperatives still work the remaining zinc ore. In the market you can buy dynamite Coca leaves and 100 % pure alcohol as gifts for the miners. In one of his dumber moves, Evo Morales tried to nationalise the mines and in response the miners descended on La Paz brandishing sticks of dynamite telling him to bugger off.