If you look at this it appears to be some sort of satellite or atmospheric communications facility. See how one of the legs is attached to the building. Also the "hole" in the roof of the building appears near the apex of the arch. Just a hypothesis.
I've seen a very similar three legged arch/antenna at a US Navy installation here on VGT before. I thought it was at Carderock ( http://virtualglobetrotting.com/map/5317/ ) but it's not.
Anyone got a better memory than me?
Submarine Overwater Antenna Test Facility
http://www.dodtechmatch.com/DOD/Lab/ViewFacility.aspx?id=71839#