One more note on the "geometry of geology"... I focused on mining as the mechanism for opening corridors and chambers for exploration along joint sets in bedrock. Of course, there is another mechanism available - dissolution and erosion of rock (typically limestone) to create cave/cavern networks.
Here's an actual cave network displaying the sub-parallel character of jointing, multiple levels and pathways, dead ends, objective hazards, etc. Really, why do we need to draw our own maps at all?
Also - this dude.