The hole in the top of the copula was for a periscope for surveying the terrain around the bunker.
The copula is part of a type Regelbau 665 bunker. The copula is 25 cm thick, whereas the walls and ceiling are 2 m thick and offered the soldiers good protection against bombardment. In the bunker was a radio and telephone room and bunks for the crew of six soldiers.
The bunker was built in the autumn of 1943. Three bunkers of this type were constructed in Hanstholm.