A military structure located near the coordinates 51.1624°N, 2.7592°E in Belgium. The specific designation 'OB' and the nature of this installation are not confirmed by the provided search results. The region of West Flanders, where these coordinates are situated, has a significant military history, particularly from World War I and World War II, including extensive fortification networks.
However, without site-specific historical records or archaeological surveys referenced in the search results, the exact function, construction period, and historical context of this particular structure remain unverified. It is listed in some contexts as a potential bunker or military relic, but definitive attribution is lacking.