Shaft & Adit Periscope and Diorama
The head shaft and lower adit next to the mill site are connected deep underground. Before shafts and adits are closed for safety, installation of a periscope or live video feed could draw visitors, generate revenue, and create a sense of the unseen connections underground.
Alternatively, adits could be closed several yards back so that visitors could enter the adit briefly and experience the space of the mine; rock walls could be painted iridescent gold or silver.
Another option might be to have an artist install a peephole tube from outside the adit or shaft into a diorama created just inside the mine. A visitor might see a tiny scene or collection of precious minerals inside.