The Air Force has a very special base sitting atop Haleakala, a dormant volcano in Hawaii. It doesn't look like any other air base because the USAF Maui Space Complex has a very special mission: Spy on objects orbiting Earth. This is how it looks:

Talking to Airman, the official USAF magazine, Capt. Shahn Rashid says that "currently it's estimated that approximately 500,000 objects orbit around Earth, and we only have the ability to track about 23,000 of them."

And any visiting aliens, of course. Don't try to fool us, Captain.