Secrets are hard to keep, and secrets that require a lot of real estate are even harder to keep. Here are six examples of large-scale efforts that managed to maintain the utmost secrecy and wound up changing the course of history as a result:
1. The entire city of Oak Ridge, Tennessee
Oak Ridge, Tennessee is now a mostly normal city that houses about 30,000 people, but it was originally established to create the nuclear bomb.
Army engineers tasked with building the infrastructure for the Manhattan Project chose the site of modern Oak Ridge and secretly created a top-secret facility with a peak population of 75,000 people. Oak Ridge was where the bulk of the nuclear material for the bombs was created.
In 1949, the site was opened to the general public and it was incorporated as a city in 1959.
2. The Kwajalein Atoll in the Pacific
Most people know Bikini Atoll, the site of many U.S. nuclear tests and the inspiration for the bikini. But Bikini Atoll was supported and largely ran by U.S. military forces at Kwajalein Atoll.
U.S. Army Kwajalein Atoll still exists and sensitive operations are still conducted there, mostly missile testing and target practice.
F-117 Stealth Fighter (Photo: Lockheed Martin)
Tonopah was a secret even among military aviators in the 1970s. Those in the know were sent to practice dogfighting against captured Soviet jets near Tonopah, Nevada.
But Tonopah had a different secret that would change military aviation. Stealth aviation was developed there and the F-117 flew many of it's test flights from Tonopah.
4. Area 51
If you don't know what the cultural significance of Area 51 is, then stop lying because you definitely know what Area 51 is. The rumors around the test site spurned its own sub genre of entertainment with big movies like "Independence Day" and video games like "Area 51."
Area 51's military significance is that it was a testing ground for the U-2 and the SR-71 predecessor, the A-12 Oxcart. Officially, the site is named the Nevada Test and Training Range at Groom Lake.
5. Wendover Army Air Base
Wendover Army Air Base was a tiny establishment when it was activated in 1942, serving primarily as a school for aviators headed to Europe.
But by 1944 a shroud of secrecy descended over the remote base with FBI agents and military police monitoring conversations and limiting movements of base personnel and their families. That's because the base was being used to train the men who were hand-selected to drop the atomic bombs on Japan.
6. Muroc Army Air Base/Edwards Air Force Base
Muroc Army Air Base started as a bombing and gunnery range in the 1930s but became a proper base and school for pilots during World War II. A few years after the war, its name was changed to Edwards.
Top secret projects began at Muroc in 1942 when the Army Air Force's first jet, the Bell P-59 Airacomet, was tested there. It also served as an early testing site for the B-29s modified to drop nuclear weapons on Japan, was the base Chuck Yeager flew from when he first broke the sound barrier, and assisted in the testing of the space shuttle.