By Thoth and Amon, click to enlarge and you'll see a method of depicting a subterranean labyrinth at once outlandish and practical; emulated, perhaps unconsciously, in Jason Thompson's fine visualizations here.
The best part? This illustration comes from Kircher's attempt to perform Egyptology without having actually visited Egypt. Yep, those are supposed to be the Great Pyramids ... but they belong to all of us now.
