The secret medieval tunnels that we still don't understand
The tantalising mystery of the erdstall
Around 2,000 strange tunnels have been found around central Europe. These aren’t like the well-known catacombs of Paris or Rome. Known as the erdstall, these passages are extremely narrow, never more than two feet (60 centimetres) wide nor high enough for an adult to walk in, and sometimes the passages become seemingly impossibly narrow, as small as 16 inches (40 centimetres) in diameter. Determining their age and purpose is made difficult by the fact that almost no archaeological evidence has been found inside any of them. A ploughshare was found in one, millstones in a couple others, but apart from that the erdstall are eerily empty. Carbon analyses of coal and pottery fragments found within point to construction dates of around 900 to 1200 AD, but no written records from the Middle Ages mention the erdstall’s existence.
This clandestine treatment would have made sense had the erdstall been built as escape routes in case of invaders, but this can’t have been their purpose. They only ever have one entrance, usually located beneath the floor of a church or farmhouse, or simply under the flagstones of a town square. After an initial drop, the tunnels run for a few dozen metres, sometimes branching or dropping down to lower levels via narrow shafts. Often, the tight tunnels widen in the middle or toward the end into small chambers with rudimentary benches or shelves carved into the earth.
No theory has yet been able to account for:
The number and distribution of the erdstall
The similarities between the many erdstall
The inconvenience of accessing the erdstall
The secrecy with which these tunnels were built and guarded
The complete lack of artefacts found within
The erdstall surely could not have been built with storage in mind, since their length and narrowness offer no advantages over a conventional and convenient cellar. And while three brave explorers in the 21st century once spent 48 hours in an erdstall, crawling to new sections whenever oxygen became scarce, it seems unlikely that they would have been constructed as hiding places, even temporary ones. Though they could have provided refuge for a small family, why would they be accessed from such public spaces? Or be too small for a large man or pregnant woman to fit through? The lack of exits is a further strike against this theory—if enemies became aware of such a tunnel being used as shelter, it would quickly become a death trap for its inhabitants. Besides, in either of these cases, one would expect at least some goods to have been left behind—remnants of food or clothing, cached or dropped valuables. Instead, there is nothing.
Natually, many have turned to ritual explanations to try to solve the mystery of the erdstall. Of course, there are the pagan theories, suggesting that these tunnels hosted clandestine rituals by those who had covertly resisted Christianisation for centuries. It is true that any heathen worship would have had to take place in complete secrecy, so severe were the Church’s punishments for non-believers. In this case, the idea that over 2,000 pagan labyrinths were painstakingly excavated and used regularly without a single documented instance of anyone being caught seems far-fetched, especially considering the erdstall’s usual location in or near Christian places of worship. To pull off such a widespread, coordinated feat would imply a conspiracy on a scale that would require a complete dismantling of our understanding of medieval history. To some, this probably makes the pagan theory all the more compelling, but most researchers don’t tend to agree. More likely than the erdstall being used to subvert the Church, they think, is the possibility that they were used by the Church.
Could the erdstall have been places left deliberately empty as some sort of folk Christian ritual? A resting place for spirits either friendly or malevolent? A feature common to apparently all erdstall is the presence of one or several “slips”—extremely narrow, often vertical sections which can only be squeezed through by most adults with some effort. The experience of this arduous passage has provoked comparisons with that of a birth canal. A German farmer and erdstall enthusiast once took a group of female folk healers on a tour through his erdstall, during which the women slid through the tight gap headfirst like an infant entering the world. Might there be an experience of rebirth built into these tunnels’ winding passages? Perhaps those who suffered from ailments either physical or spiritual were sent down into the depths to undergo a sort of renewal, intended to bring them back up into the light as if born again. Reemergence would parallel that of Christ rising again after three days dead in a cave.
This theory is tempting because it turns the narrowness, darkness, and emptiness of the erdstall into a feature of the experience, contributing to the feeling that one was being laboriously brought forth into the world. While the small niches carved into the tunnels’ walls could have held the lamps of builders during excavation, a penitent might have gone down with nothing but their hands to find their way. Christians have long used things like rosaries and labyrinths as physical guides for contemplative prayer, so maybe the erdstall’s branches and chambers could have functioned similarly, offering designated places for specific prayers or invocations. And the imagery of the birth canal has parallels in other Christian traditions depicting Christ’s enthronement and side wound.
Of course, this doesn’t explain why there are no contemporary writings attesting to the erdstall’s existence, but many religious objects and images from the Middle Ages went undocumented. We still don’t know why so many manuscripts contain images of knights fighting snails, nor why churches sometimes have carvings of female figures pulling open their genitalia to the world. It is all too easy for these things to be considered unremarkable until they become a mystery. And, without much rigorous study investigating the erdstall, it is likely that a satisfying answer may be a while off, if one can even be found.
Perhaps I favour the rebirth explanation because, during the four years of my undergraduate degree at the University of Glasgow, I walked past a distinctive sculpture outside the geology building almost every day. The Glasgow Geological Society notes that it was carved from an old railway culvert and deftly glosses over any reference to its shape by referring to it simply as a “strange monument”. However, to all on campus, it was quite plainly the Stone Vagina. Normally, the Stone Vagina would be spared little more than a glance or remark by those passing. However, on nights of revelry, when spirits were high and drinks had been drunk, it was not uncommon to give in to the urge that the stone so invariably provoked and stop to squeeze oneself through.
Dwarves.
Dwarves did it.
Reading this triggered my anxiety ....