It's a large complex (bunker) made out of thick & heavy concrete and was constructed onto old wood pilings. This bunker has been sitting on the beach since it was constructed back in 1942. One of the locals told me that the military housed ammunition in the bunker along with a few dozen personnel to watch out for ships, boats and submarines that may be lurking around in the area during the war.
You can walk all around it (outside of it) as it has become a tourist attraction for many who visit Cape May Point and/or Sunset Beach. Matter of fact, bring your beach chairs and beach blankets and you & the family can enjoy an afternoon on the beach and a picnic lunch while there.
Nearby you can walk over and visit the Cape May Point Lighthouse, the World War 2 Lookout Tower, Sunset Beach Shopping (3 gift shops), the Sunset Beach Grille or take in a round of miniature golf. All parking is free and most attractions within walking distance are FREE or low-cost. It's a beautiful area to spend the afternoon with the family while visiting the Jersey Shore.