Edition of 7

Cheyenne Mountain Directorate (CMD) was built to protect personnel and equipment from a thermonuclear weapon attack. It serves as an underground surveillance post where the U.S. and Canadian governments defend North American borders by scanning for enemy intruders.
The complex is built inside a hollowed out natural mountain. To protect the mountain’s integrity and to prevent implosion, 110,000 rock-bolts (6 to 32 feet in length) and 7,164,080 square feet of wire mesh support the mountain’s interior tunnel system. Its structure and supplies can sustain life within the mountain for at least one month.