Judging from the abundance of 440 volt hookups in the building, this likely was some sort of machine shop.

Likely decimated by vandals.

The office/bathroom is inside this building, and the first building in the album is visible through the trees in the background.

Even older looking stairs - the mine has history back to the 1800s, but this is probably not that old. The building on top of it appears to have burned, leaving behind electric wires and boxes.

Tree blocking a doorway.