A military bunker located in France, near the coordinates 48.22635260707697, -4.383016586036062. The designation 'Feldm. OB' likely refers to a field command observation bunker, a type of military structure used for surveillance and command purposes during wartime. France has a long history of military fortifications and bunkers, particularly from World War II and the Cold War era, reflecting its strategic importance in European defense.
While specific details about this particular bunker are not provided in the search results, it is situated within a country known for its extensive network of military installations and defensive structures.