The Cheyenne Mountain Complex is yet another government facility that was built into the side of a mountain during the Cold War. Located just outside of Colorado Springs, Colorado, the facility is home to a variety of government operations, including NORAD (North American Aerospace Defense Command).
The operations center lies inside a tunnel bored a mile into the mountain — a tunnel that's designed to route a blast’s shock wave out the other end past its 25-ton blast doors. Inside the mountain you’ll find several intersecting chambers and 15 freestanding buildings — 12 of which are three stories tall.
Like all good apocalyptic hideouts, Cheyenne Mountain is designed to be self-sufficient.It can protect its inhabitants from nuclear fallout and biological and chemical warfare through its elaborate air-purifying system that filters out harmful pathogens, chemical particles and radioactive material. It even has powerful springs that can absorb energy from earthquakes and bombs. Electricity comes from Colorado Springs, but there are six 1,750-kilowatt diesel generators for backup. There’s also a massive underground water supply — four excavated reservoirs hold 1.5 million gallons of water. In fact, they’re so large that workers sometimes cross them in rowboats. Can you say post-apocalyptic pool party?