Most Secret Military Bases

4. Pine Gap, Australia

Jointly operated by Australia and U.S., Pine Gap is a satellite tracking station located in the Northern Territory, down under. Though government officials refuse comment, many believe the site controls U.S spy satellites passing over China, Russia and the Middle East.

Pine Gap maintains security through a five mile no-fly zone and strict policy of no outside electricity, essentially isolating the site. Strategically located in a remote location far from international waters, there is no way for its signals to be intercepted making it a key control center for clandestine operations like the U.S. prone program.