Diego Garcia harbors more than one secret, some reports claim that the military is harboring an underwater base that allegedly utilizes alien technology. There seems to be photographic evidence of the existence of under water bases as well. A Popular Mechanics investigation TRACKED DOWN SOME OF THE MOST INTERESTING ACTIVE MILITARY FACILITIES AND SPOKE WITH BRAD SCHULZ, VICE PRESIDENT OF FEDERAL ARCHITECTURE AT HNTB. HERE IS WHAT SHULTZ HAD TO SAY ABOUT DIEGO GARCIA.
"There's a certain amount of logistical difficulty" with ultra-remote facilities like Diego Garcia, and shipping materials can be costly. Diego Garcia's remoteness, though, allows it to be a key hub for tracking satellites, and it is one of five monitoring stations for GPS. Additionally, the island is one of only a handful of locations equipped with a Ground-based Electro-Optical Deep Space Surveillance system for tracking objects in deep space. As an atoll, the land itself is rather oddly shaped, too. From end to end, Diego Garcia is 34 miles long, but its total area is only 11 square miles.” ~Shultz