OB 15,5cm Geschütz is a German World War II coastal artillery bunker located in northern France. This fortified position was part of the Atlantic Wall defenses constructed by Nazi Germany along the French coast to defend against potential Allied invasion. The designation 'OB' refers to 'Offener Bau' (open construction), indicating a reinforced concrete structure designed to house heavy artillery pieces.
The 15.5cm caliber designation confirms this was a medium-caliber coastal defense gun emplacement, typical of German defensive installations during the occupation period.