Turm III of Batterie Todt was completely destroyed by an accidental explosion in August 1945. The blast, which must have been enormous, pushed away part of the bunker walls on the left side and caused the 3.5 meters thick ceiling to shift and collapse. The firing chamber that originally housed the Krupp 380mm (15 inch) SK C/34 naval gun inside a C/39 armored turret (Ger: Bettungsschiessgerüst) is filled up with rubble and debris from the explosion.
This bunker is part of Batterie Todt which was constructed between 1940 and 1942 together with other German coastal batteries like Batterie Oldenburg along the French coast in preparation for the Invasion of Britain, codenamed Operation Sea Lion. The battery had a total of four casemates or “Turms” fitted with 380mm naval guns.
The battery became operational in January 1942 and was officially opened in February of the same year by Admiral Karl Dönitz and Admiral Erich Reader. Although initially named Batterie Siegfried, the name was changed to Batterie Todt just days before the opening, to honor German engineer Fritz Todt, head of the Todt Organisation, who died in a plane crash on Februari 8th 1942.
You can visit this bunker Turm III as part of Batterie Todt in the Forest of Haringzelles in Audinghen, Cap Gris Nez, France. You can also visit Turm I, which is now Musée du Mur de l’Atlantique, and Turm II and Turm IV nearby.