TIL about erdstall , more than 600 tunnel found across Europe of unknown origin but are believed to date from the Middle Ages
TIL about erdstall , more than 600 tunnel found across Europe of unknown origin but are believed to date from the Middle Ages

Erdstall - Wikipedia

Your title is a bit misleading. It's not one tunnel or an interconnected tunnel network. And most of the tunnels are pretty short. No more than 50 meters most of the time.
https://en.wikipedia.org/wiki/Erdstall
But what if, though? Maybe the mole men do exist.
My kid is obsessed with Henry Danger. It's corny as all get out, but can be pretty funny. This is one of the better scenes and entirely related: https://youtu.be/a3q4IXx7zeY?feature=shared&t=117
Has anyone alerted the Fantastic Four?
End the mole men patriarchy! Mole women unite!