The Octave Mine in Arizona has a reputation, not just for ore output, but also for ghosts, particularly one referred to as the "Blue Devil." It has been the focus of investigations and even the show "Ghost Mine."
What was once the greatest source of gold in the US still has 25 miles of tunnels beneath the 266 acres awaiting more retrieval by some daring enterprise willing to pay $4.8m for it.
The Blue Devil ghost is said to haunt the 25-miles of tunnels. The legend says a 7-foot man named Staten did horrible things to the men in the mines, torturing and killing miners.
Some reported seeing devil-horned-head looking shapes in the walls. Interestingly, my brother-in-law in West Virginia was working in an area that was carved out near a dam. When they were done cutting the rock, the men went into the cavern and saw what they believed was a devil head in the rock. Some men fled and did not come back in there until concrete was poured, filling it in.
If you're interested in what the $4.8m price tag offers, here's the Zillow link.