IronMiners.com has gorgeous tours of abandoned American iron mines. These are gloomy, lovely, spooky places.
And I love the language of these underground zones. For example, about the entrance to a New York mine started before the Revolutionary War, I learn that "entrance" is the wrong word. Say "adit" instead:
After approximately 35 feet, the adit meets the stope. A water filled winze with log cribbing stands across from the adit within the stope. The mine is said to be as deep as 70 feet. This winze accesses a lower stope.