Cheyenne Mountain Complex is a protected, closed-to-the-public underground facility situated inside Cheyenne Mountain in the southwest corner of Colorado Springs, Colorado. The unique concept of a tough command and control center was actualized as a shield against long-range Soviet bombers at the peak of the Cold War in the late 1950s. Excavated by the Army Corps of Engineers, the complex became fully functional as the North American Aerospace Defense Command (NORAD) on Feb. 6, 1967. Today, the facility acts as a NORAD staff training site. So what makes Cheyenne Mountain Complex the world’s most secure building? First, it’s located under 2,000 feet of granite. The facility has 6 tunnels and each tunnel is 3 stories tall. The complex is secured against seismic activity and nuclear explosions and is also strengthened against electromagnetic pulse attacks. The two main blast doors leading to the complex are 3½ feet thick and weigh over 20 tons, taking an average of 45 seconds to shut. The doors are only closed in times of emergency. In fact, they’ve only been closed once, and that was during the 9/11 terrorist attacks. The complex can withstand a 30-megaton atomic blast at a range as close as 1.24 miles.
