A rare look inside the heavily guarded compound where Lockheed Martin builds the THAAD missile
A Terminal High Altitude Area Defense (THAAD) interceptor is launched during a successful intercept test, in this undated handout photo provided by the U.S. Department of Defense, Missile Defense Agency.

TROY, Alabama — The crown jewel of U.S. missile defense systems comes from an unlikely place: a 4,000 acre compound nestled in the quiet woods of a southern Alabama town.

For the first time, Lockheed Martin opened to the media its heavily guarded compound in Troy, Alabama, where it builds and breeds America's THAAD, or terminal high altitude area defense system. The process to open up the facility took more than a year of security approvals and was conditional that no photography or recording devices could enter the complex.

"No other media has been back here in the manufacturing area," Jason Crager, Lockheed's site director, said earlier this week during the drive up to a nondescript building tucked into the trees. "And not too many people in the world can say they have stood either in front of or beside a THAAD missile."

THAAD, one of the world's most advanced missile systems, can target and blast incoming missiles. Once fired from its truck-based launcher, each interceptor uses kinetic energy to deliver "hit to kill" strikes to ballistic threats instead of traditional warheads.

"Think of it this way, it's like a bullet hitting another bullet," explained Lockheed spokesman Mark Johnson, using a pointed finger from each hand arcing toward each other in a way to mimic the strike.

In 2008, Lockheed Martin delivered the first THAAD battery to the U.S. Army. Since then, the system has been deployed to Guam, South Korea, Romania and Israel. The U.S. has secured multibillion-dollar deals to sell the missile defense system to the United Arab Emirates and Saudi Arabia.