This bunker, the first cleared by volunteer members of the association, is a Regelbau 605 type gun shelter.
Its construction was not completed in June 1944, and the heavy sliding doors were never installed in it. The R.605 shelter is a rare model on the Atlantic Wall (two examples in France) which served as a garage for anti-tank guns or for vehicles. Today, there are only five models of this type left in Europe.
The construction of this model required 1600 m3 of rubble, 900m3 of concrete and 45 tonnes of scrap metal.
Aerial photographs appear to show that an unconcreted enclosure had been built nearby to accommodate a cannon. A hold was cleared near this location.
The R.605 consists of three rooms, with two cells (1) closed by an armored sliding door and a shelter for the servants (2).
On Hillman, the only example of economical concrete block design is served by a concrete ramp located on the side of the road. Only the left cell was fitted with a wooden door in anticipation of a sliding armored door. The cell on the right appears to have served as storage for equipment. It should be noted the presence of a Tobruk (4) on the right side of the structure which ensures its protection.