The Kellerlabyrinth is a maze of tunnels under the streets of Oppenheim, Germany. They were constructed according to need (as opposed to following some overall architectural scheme) over the course of at least six hundred years. I first read about it in this blog post.
I was working on a 30 Years War sandbox around that time, which made me even more excited than I should have been about Better Than Any Man when it came out a couple months later. The story's main town of Karlstadt is fictional, but another location on the map isn't: Wurzburg, which, by LotFP rules, is only a three days' walk (unencumbered) from Oppenheim. So this would actually make a pretty good follow up if any of my players ever manage to live through BTAM (seriously none of them even know about the Insect Cult).
This map doesn't even come close to depicting the entire tunnel system, which apparently could have more than 600 rooms in it. Most haven't been discovered yet because tunnels have collapsed or been intentionally blocked off, so you can think of this as one of the undiscovered sections. Some areas go five or six levels deep, but I think this is just enough visual complexity to not be overwhelming.
The side bar on the right is just general guidelines to use when stocking it, but I ran out of space. There also would have been plenty of grafitti (most people were at least literate enough to sign their own names by this point), and probably drinking halls like this modern one set up:
|How many historical attractions have bars built right in? (okay probably a lot actually but shut up)|