A German World War II-era coastal defense bunker, identified by the designation 'KüVer 413 (Var.)' located near Vlaardingen, Netherlands. The prefix 'KüVer' is a standard German abbreviation for 'Küstenverteidigung' (coastal defense), and the '(Var.)' suffix indicates a variant type. This site is part of the broader Atlantic Wall fortifications constructed by Nazi Germany along the occupied European coastline.
Specific details regarding its construction year, armament, and crew complement are not confirmed in the available sources.