The bunker complex, designated as Hill 61 and codenamed Hillman by the British, was attacked on 6 June 1944 by the Suffolk Regiment and the fortress finally surrendered the following morning.

Built at 61 m (200 ft) above sea level, the complex offered direct views of the landing beaches, as well as the mouth of the Orne river.

Attacking at approximately 1305, Hillman was initially outflanked to the north, where the Royal Engineers cleared mines and barbed wire using Bangalore torpedoes.

The company advanced into the German trenches but faced heavy machine gun fire (Captain Ryley being killed) and retreated.

Historians suggest that the strong resistance of Hillman contributed to preventing the 3rd Infantry Division taking Caen as planned by the evening of 6 June.

In 1989, Madame Lénaud, a resident of Colleville-Montgomery and the owner of the land where one of the bunkers was built, donated it to the Suffolk Regiment to commemorate what happened during the war.

Since 1990, the volunteers of the Association "Les Amis du Suffolk Regiment", and with the support of the local community, have preserved and continued to restore the Hillman Fortress, including Colonel Krug's command post.