This inconspicuous Bullion Depository building just off the Dixie Highway may not seem too tough — until you realize it's one of the most secure locations in the world. There's a reason why "Fort Knox" is synonymous with high-end security.
The U.S. Army post around the U.S. Bullion Depository, Fort Knox, isn't that much different from any other military installation. To gain entry, a civilian can sign onto post at the visitor's center. But even troops stationed there can't just casually swing by the depository.
Not much is truly known about the inner-workings of the depository; there certainly are no photographs or schematics available. What is public knowledge is only what's visible from the outside, interviews resulting from the 1974 tour, and first-hand accounts from the former, extremely-select handful who've set foot inside.
From the outside, you can see the many fences that lay between the building and the highway. Several of them are said to be electrified. Each corner of the building has a guard tower manned by an unspecified amount of security guards who watch over each sector. The land between the fences is also said to be mined.
Construction on the building itself was completed in December, 1936, and the known building materials include 16,000 cubic feet of granite, 4,200 cubic yards of concrete, 750 tons of reinforced steel, and 670 tons of structural steel. All of this for a 2-story-tall building with a 1-story basement — sounds pretty secure, right?
In addition thousands of pounds of steel and stone, there's an entire battalion of U.S. Mint Police that cover the place.
The politicians and journalists who were granted access to the building in 1974 entered through the 20-ton steel door and got to look into one of the many compartments. That compartment held 36,236 gold bars, stacked from floor to ceiling. At the time, the gold was valued at $42,222 per Troy oz., which meant they got to see $499.8 million of gold.
The rest of the security measures are up for speculation. The Fort is rumored to be outfitted with laser wire and seismographic sensors to ensure no one approached undetected. The corridors can, apparently, be flooded at a moment's notice. And security measures are constantly re-worked to improve and re-improve before anyone knows better.