This was an experience I will never forget. I was fortunate enough to explore one of the mines in the famous silver mountain in Postosi, Bolivia. I met a guy who knew a guy...you know how it goes...who knew some of the local miners. All that was needed was to buy a few presents for them: a bag of coca leaves, some alcohol (98% volume), a couple of sodas and a stick of dynamite. Yes, one can legally purchase sticks of dynamite at the local market in Potosi.
It was a chilly day yet after penetrating deep into the mine shaft the air got warm and was filled with dust. The paths felt claustrophobic and you could easily get lost in the complex mesh of connecting shafts. If you didn't watch your step you could suddenly fall through a vertical vent to a level (or many levels) beneath you.
I didn't see many old miners (the average life expectancy here is said to be 40 years of age) but I met a couple of kids who told me they were 14 years old. We hung out with the miners for about 5 hours, mostly drinking what tasted like rubbing alcohol, chewing on coca leaves and blowing stuff up with dynamite. They wanted to know all about my life and my experiences and I about theirs. So there was a lot to talk about. After I came out of the mine I found a new appreciation for open spaces and fresh air.