Carved deep into the granite of Colorado’s Front Range lies one of America’s most secretive Cold War creations: the Cheyenne Mountain Complex. Built to survive nuclear war, this underground fortress housed command centers, power plants, reservoirs, and even living quarters—an entire city inside a mountain. Protected by 25-ton blast doors and thousands of feet of rock, it became the nerve center of NORAD, watching the skies day and night.

But beyond its serious mission, Cheyenne Mountain captured the imagination of the world. From WarGames to Independence Day to Stargate SG-1, Hollywood transformed it into a symbol of ultimate survival. In reality, life underground was far more human—long shifts, sealed doors, and constant vigilance. So why did the United States build a city inside a mountain, and what really lies behind those blast doors? Stay tuned as we uncover the full story of America’s ultimate doomsday bunker.