Sort of on topic, the Hellfire Caves are really quite something, if you get a chance to visit them. https://en.m.wikipedia.org/wiki/Hellfire_Caves https://en.m.

Sort of on topic, the Hellfire Caves are really quite something, if you get a chance to visit them. https://en.m.wikipedia.org/wiki/Hellfire_Caves https://en.m.wikipedia.org/wiki/Hellfire_Caves 400m deep, dug by hand, to use the chalk for the road between Wycombe and West Wycombe. Quite the feat of engineering. Wonderfully creepy inside as well.