Bunker B/ON-1531 is a German World War II defensive structure located in De Haan, West Flanders, Belgium. Situated along the Belgian coastline, this bunker was part of the extensive Atlantic Wall fortifications constructed by Nazi Germany to defend against Allied invasion. De Haan, a coastal town known for its Belle Époque architecture, became a strategic location during the war due to its proximity to the North Sea.
The bunker remains a tangible reminder of the region's wartime history and the broader Atlantic Wall system that stretched across occupied Europe.