https://en.wikipedia.org/wiki/Erdstall https://en.wikipedia.org/wiki/Erdstall https://en.wikipedia.org/wiki/Fogou https://en.wikipedia.org/wiki/Fogou Pretty f

https://en.wikipedia.org/wiki/Erdstall https://en.wikipedia.org/wiki/Erdstall https://en.wikipedia.org/wiki/Fogou https://en.wikipedia.org/wiki/Fogou Pretty fascinating the sheer number of different types of mediaeval tunnels across Europe and their presumed uses