When we had our rather buggy walk at Vischer Ferry Nature Preserve, we discovered this strange-looking building.
The ground floor was completely open apart from the left-hand side which was not much larger than a staircase I would think. In fact, now I think about it - why has it got a small doorway in addition to the large opening - inside it was all one space. Above, there were electricity cables going in (on the far side) and a tall pole with a radio antenna or similar (pictured). Whether the sign on the internal door means that it is some kind of federal facility or just that it is protected by federal law I don't know.
It was weird in a kind of creepy way.
Anyone know what it is? Anyone want to make something up? It's here if you're interested.