I do not have much of a motivation to explore old mine shafts. Usually, the shoring and support was furnished by local timber and has deteriorated over the years making any entrance extremely dangerous. However, I must admit I have explored a few mines that were cut into solid rock. If you are looking for minerals, I would note that these mines are usually still privately owned and entry into them can constitute trespass. I do appreciate all the work it took to cut these tunnels into the rock.