Hillman Fortress - Credit: Wikimedia Commons
The Hillman Fortress (, ) was a German bunker complex and command post built during the Second World War and located near Colleville-Montgomery in Normandy, France. 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. The delay in taking the bunker complex has been cited as a reason for the Allies not completing their major D-Day objective of taking Caen. Read more on Wikipedia
Source: en.wikipedia.org