OB 5cm Kw K is a World War II-era German-built bunker located in northern France, near the coast. The designation 'OB' refers to 'Offene Bauweise' (open construction), indicating a lighter defensive structure compared to fully enclosed casemates. The '5cm Kw K' designation suggests it was designed to mount a 5 cm Kw K (Kampfwagenkanone) gun, likely for anti-tank or defensive purposes.
This type of bunker was part of the Atlantic Wall fortifications constructed by Nazi Germany to defend occupied France against Allied invasion.