51°24'25.56"N 1°01'06.83"W - and you need to go in really close, maybe 900 feet.
The towers are obviously lightning conductors, as seen around the Air Force Titan pads at Cape Canaveral. But the "greenhouse" structures encircling the bunkers and covering the corridor leading off to the north-west; one huge Faraday Cage? Whatever it is, I guess you can't be too careful with those nukes....