A tour of the cooperative mines is a shocking experience. You will be taken down into the mines through the cramped tunnels, and meet the miners who have to work in these conditions all day long.
We were lucky enough to meet a miner who had just completed a hole for dynamite, so we got to see an explosion. The fuse was lit and we had one minute to get far enough away to hear the explosion from a safe distance. You could feel the explosion shake the ground.
Before going into the mine, we were encouraged to buy the miners presents, such as dynamite, coca leaves, or cigarettes. I would recommend doing this as well; just buy something. It is inexpensive and gets you some interesting stories!
Be prepared to get dirty. Protective clothing is provided, but the mud still gets in, and you will have to crawl on the floor and squeeze through some holes in the wall.