Battery Oldenburg is a German artillery battery, built during World War II as part of the Atlantic Wall, and situated east of Calais. The battery began in 1940 with artillery guns in an open emplacement. The Organisation Todt built casemates around two 240mm guns during the war.
Both casemates or Turms (towers) are 35 meters long and 15 meters high, positioned in a slight offset from each other to gain a broader range with both guns. Turm East and Turm West housed guns of Russian origin that were captured by the German army during World War I and re-chambered by Krupp from 255mm to 240mm.
Both casemates are 35 meters long and 15 meters high above ground level. The western of the two casemates, Turm West is two storeys deep, while the eastern casemate, Turm East, is three storeys deep.
Besides the two casemates, battery Oldenburg has a combined fire control and hospital bunker, which still has a beautiful fresco and other paintings, ammunition bunkers and personnel bunkers. Behind the two casemates and fire control bunker is the barrack site used by Organisation Todt.
Battery Oldenburg surrendered to Canadian forces in 1944.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.