Let me start off by saying this is not for everyone. A trip to the Silver Mines of Cerro Rico in Potosi is viewed differently by many people. On one hand you're getting a glimpse of a harsh lifestyle that has sustained the local Bolivians for generations. On the other hand, as a tourist, you're possibly doing more harm than good turning the mines into an "attraction". A typical visit to the mine will have you stop at the miners market to pick up bags of cookies, cigarettes, cocoa leaves, dynamite, ammonium nitrate, and other explosives. You get decked out head to toe in colourful outfits and head on in, offerign a sacrifice to the local gods. Inside, you walk around, meet some workers and offer them your goodies. Cookies for the younger teenagers and explosives or cocoa leaves for the rest. Some parts you need to crawl on your hands and knees or flat on your stomach (all while heaving your bag of dynamite around!) Some workers have mined for silver all their lives and don't even speak Spanish or Quechua. For many it is a family business, where they may own an 'area' of the mountain instead of being part of the state controlled areas. This aspect gives many of them a sense of freedom, they are their own bosses, working as hard as they want...which is nice to see. The issue is really that there are no safety precautions in place. A collapse can happen at almost any time and the air quality can be deadly. You only get to visit the 'higher' tunnels closer to exists, where air quality is not as big an issue, deeper down, where they are drilling, they get paid much more, but we were told that life expectancy is only 4 years, although most people only 'sacrifice' themselves at that job for a few months or maybe 1 year. A real eye opener and jaw dropper. Consider it if you're not claustrophobic.