According to eyewitness reports, the tunnel bunker in the Propsteiberg was built by the local construction company Beele using forced laborers in the autumn/winter of 1943/44 and was intended to provide shelter for around 400 people.
The construction was a reaction to the increasing air raids by the Allies, in which Belecke represented a potential target as an armaments industry location and railway junction.
The accessible part of the bunker has a total length of 127.1 m. The length in the east-west direction is 87.7 m, the length in the north-south direction is 39.4 m. The bunker has a total area of 239.2 m sqm and a total volume of 445 kbm. The dimensions roughly correspond to the specifications in the "Ordinance on the construction of air raid shelters" of September 17, 1943.