From what little I have heard of, that is one of those 'places' that rank up there like the every living "Puzzle Palace". Other wise known as the Fort Meade. Home of the National Security Agency, among other things. Back when I was a Cryptologist for the USA Navy in the 1980's that was the place of ultimate intelligence repository. Some where you go if you were NOT suppose to be. Places which I got to work at were, shall we say known of but not talk much about. Like Edsel, Scottland (56.809273, -2.605760), Adak, Alaska (51.942440, -176.600703), Diego Garcia (-7.279341, 72.369162), Rota, Spain (36.656597, -6.365077) to name a small number or now ghosts. I later found there were many more places that were closed down over time http://www.navycthistory.com/NSGStationsHistory.txt).
But I only recently heard of Pine Gap from a Youtube video mentioning places you're not allowed into. Turns out that is because of the low-life traitor Snowden, who blabbed about it among other things