Underground Bunkers and Secret Bases

Governments really did build hidden cities under mountains and luxury hotels. The rumored alien base under New Mexico is another story.

During the Cold War the United States built a network of hardened sites to keep the government running after a nuclear attack. Cheyenne Mountain in Colorado, carved into granite behind massive blast doors, became fully operational in April 1966 and still houses NORAD and U.S. Northern Command functions. Beneath the Greenbrier resort in West Virginia, a bunker for Congress was kept secret for about thirty years until a journalist revealed it in 1992. Raven Rock in Pennsylvania served as an alternate Pentagon.

Connected dossiers

Area 51: The Secret Base in the DesertComparable case · Secret government facilities.The Underground City of DerinkuyuComparable case · Underground refuges, ancient and modern.

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How to read the labels

Hero image: A 20-ton blast door closing inside the Cheyenne Mountain Complex, Colorado. Photo: U.S. Air Force (Joann Missey) · Public domain · via Wikimedia Commons. Evidence labels describe the written claims, not the image. Version 1 · updated 2026-10-22.