The bunker at Langdon Hole was built in late 1942 as one of the joint operation headquarters at Dover’s two underground wireless outstations. The Dover headquarters was based in the Dumpy level tunnels at Dover Castle, and Langdon Hole was thus often referred to as “Dumpy B”. The other station, “Dumpy A” was located at Long Hill. The structure is reminiscent of the coastal artillery deep shelters found nearby in Dover, having the same structure of vaulted steel sheeting supported by colliery hoops and two inclined entrance shafts, An unusual feature is that one of these contains a set of rails used for hauling heavy equipment in and out of the bunker.
The underground tunnels are made up a pair of parallel longer tunnels, one set originally contained the wireless station and the other was used for accommodation; a number of spur tunnels contained power generation equipment and ventilation plant. The ventilation towers with moveable eyeball-like nozzles are an unusual feature of the tunnels, and are only otherwise found locally in the Dumpy tunnels at Dover Castle. These provided cooling to the facility.