Bunker B/ON-0122 is a World War II-era German military bunker located at the former Gontrode Airfield in East Flanders, Belgium. This defensive structure was part of the extensive network of fortifications established by Nazi Germany during their occupation of Belgium. The bunker served as a hardened shelter and defensive position for airfield personnel and equipment, typical of the Regelbau standard designs used throughout occupied Europe.
Situated in the Flemish countryside near Gontrode, it represents the military infrastructure that once dominated this agricultural region during the war years.