A medieval tunnel system, formally known as an “erdstall,” was discovered by the Saxony-Anhalt State Office for Heritage Management and Archaeology (LDA) during excavations near Reinstedt in Saxony-Anhalt, Germany.

The discovery was announced in a January social media post saying that “a very special discovery was documented at the end of 2025 in the area of a Middle Neolithic burial site.”

Erdstalls, a combination of Middle High German’s erde (“earth”) and stelle (“place”), are tunnel systems believed by researchers to have been constructed in the Middle Ages, though their precise dating is a challenge, as they are commonly found empty. 

Even so, a horseshoe, a fox skeleton, and the bones of several other small mammals were unearthed in Reinstedt, according to the LDA.

The Spanish-language publication La Brújula Verde (LBV) added that archaeologists had also discovered a layer of charcoal in the erdstall’s lower levels, believing that the fire was “short-lived, perhaps merely a source of light.”

A pile of large stones found by archaeologists near one of the tunnel’s entrances may have been stacked there as a way to seal off the entrance, LBV said.

LBV further noted that the Reinstedt erdstall’s height ranged between “one and 1.25 meters, with a width of between 50 and 70 centimeters, and in some stretches, it featured a gabled, vaulted ceiling.”

According to the LBV, archaeologists also discovered the remains of a possible Bronze Age burial mound near the erdstall and Neolithic tomb.

Thousands of similar tunnel systems have been discovered across Europe. Nevertheless, their purpose has been subject to decades of theory and debate.

Some researchers believed that these tunnels were used as temporary hideouts or escape routes, like those used by Jewish rebels during the Bar Kochba revolt.

LBV, however, explained that the late archaeologist Lambert Karner disregarded this theory in his 1903 book “Künstliche Höhlen aus alter Zeit,” claiming that, based on the tunnels’ design, such a use was impractical.

According to LBV, Historian Anton Haschner proposed that the tunnels may have been “empty symbolic tombs, erected by medieval settlers in their new settlements as dwellings for the souls of their ancestors, awaiting the Final Judgment.”

“Other interpretations insist on their possible use for initiation rituals, as places of spiritual retreat, or simply as temporary hideouts for people and valuable goods during periods of instability, although the absence of a second exit complicates this last explanation,” LBV went on.

“Their location, often in the basements of old farmhouses, near churches, cemeteries, or in remote forests, adds further layers of mystery to their original purpose.”