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 Citadelle of Quebec is an active military installation and official residence of both the Canadian monarch and the Governor General of Canada. It is located atop Cap Diamant, adjoining the Plains of Abraham in Quebec City. The citadel is the oldest military building in Canada, and forms part of the fortifications of Quebec City, which is one of only two cities in North America still surrounded by fortifications, the other being Campeche, Mexico.
The first fortifications in Quebec were built by the Governor General of New France Louis de Buade, and completed just in time for the Battle of Quebec in 1690.
After the British conquest in the second half of the 18th century, the problem of Quebec City's defences grew more acute.