Tours of this gold mine available in Cripple Creek, Colorado. Sounds like a neat experience:

http://goldminetours.com/mkminetour.htm

I took the tour in 1975. My grandfather wqas a hard rock miner in the Cripple Creek District 1900-1903. The descent in the darkness was an interesting experience. It gave me a chance to find out what life was like for him even though he died years before I was born.

I recommend the trip for anyone interested in mining, especially in an area the supported four rail lines.

I haven't been back to Cripple Creek since gambling was approved, but I have been to Blackhawk and Central City and disappointed to see the changes.