Cerro Rico , or the rich mountain, supplied Europe with it´s silver for 300 years. The Spanish mainly used slave work to mine the silver, and during these 300 years it is estimated that 9 million people died working in the mines, or in processing workshops, due to the hard working conditions or the poisonous materials used in the processing.
At the foots of Cerro Rico, the Spanish built the town of Potosi, in it´s peak 120,0000 people lived in the city, making it the second biggest city in the world at that time, after the decline of the mines though, most of the people left, and now the city is home to 30,000 inhabitants.