We Still Don’t Know Why Medieval Europeans Built Their Mysterious ‘Erdstall’ Tunnels

 Sometimes it feels like every corner of our planet has been mapped, catalogued, portioned up, explained, and generally drained of any of its mystery. Which is what makes the existence of the strange subterranean systems known as “erdstall” tunnels all the more surprising.

These unexplained passages number in the thousands, and are located in a mix of European countries. There are around 2,000 known erdstall tunnels throughout Europe, with the highest concentrations in Bavaria (some 700), and Austria (another 500). They have also been found in France and Great Britain. Researchers are at a loss as to their origins and uses.

There are countless earthen tunnel systems around the world, but a few features distinguish erdstall tunnels. The term “erdstall” is German, loosely translating to “earth stable” or “mining tunnel.” The label has come to be associated with a very specific variety of human-made subterranean passages. Generally speaking, an erdstall system is made up of narrow tunnels that have been carved into a smooth, ovular shape, aligned either vertically or horizontally. The passages tend to be notably tight, measuring only a few feet tall by a few feet wide. Some of the discovered erdstall tunnels contain crude structures in their terminus that could have been benches, although who would have wanted to sit there in the dark is unknown.

Another aspect of the tunnels are choke points called “schlupfs” or “slip outs.” These uncomfortably tight holes would act as transition points between portions of the passages dug at a higher or lower elevation, requiring anyone passing through to contort and squeeze their way by. Erdstall tunnels are also notable for having only one point of entry and exit, usually tucked away in the footprints of old settlements, or even hidden in the wilderness. This feature made the air flow through the tunnels nearly non-existent....<<<Read More>>>....