Entry to the erdstall Ratgobluckn at Perg, Austria.
Its passages are high enough for touristic access.
Some are so small that explorers have to get down on all fours.
They are also very narrow, averaging about two feet across.
Most tunnels are longer than twenty meters, but not more than fifty meters long.
A schlupfe can also occur horizontally connecting two tunnels in the same level.
Erdstall tunnels are also known to have only one narrow concealed entry point with no separate exits.
The atmosphere inside is dark and oppressive.
A vertical slip hole.
Photo credit:Josef Weichenberger/Wikimedia
A horizontal slip hole.
Researchers have wondered what purpose the final chamber could have served.
Was it used to store food?
Did they hide villagers when their homes were raided by passing hordes?
Not many evidences could be gathered from the tunnels.
Most of them are almost completely empty and appear to be swept clean.
A few contained some medieval tools like iron plowshare and heavy millstones.
The tunnels show no sign of mining.
They are too small to be used as cellar, and they make poor space for habitation.
They are definitely not tombs as no human remains have been found.
The only remaining theory is that they were hideouts.
Erdstall tunnels are found all over central Europe.
In Bavaria alone, there are about 700 such tunnels.
In Austria, there are about 300.
Some are found in France, Spain and Great Britain.
In total, some 2,000 tunnels are known to exist in Europe.
Photo credit:Peter Forster
Sources:Spiegel/Showcaves/Wikipedia
