OB 21cm Geschütz is a German coastal artillery bunker located in Norway, built during World War II as part of the Atlantic Wall fortifications. The designation 'OB' refers to 'Oberbau' (upper structure), while '21cm Geschütz' indicates it housed 21-centimeter artillery guns. This type of bunker was designed to provide long-range coastal defense against Allied naval forces.
Norway's strategic position made it a key location for German military installations during the occupation period from 1940 to 1945.