See a Massive, Self-Sufficient Military Complex Inside a Mountain

The Pentagon's Cheyenne Mountain Complex in the US State of Colorado can really boggle the mind in terms of its scope and sophisticated equipment.

The North American Aerospace Command (NORAD)'s clandestine Cheyenne Mountain Complex in the Front Range of the Rocky Mountains near the city of Colorado Springs is one-of-a-kind in terms of its scope and its role as the fortified home of the US defense arsenal's most advanced tracking and communications equipment.

The Cheyenne Mountain Complex is a military installation and nuclear bunker located at the Cheyenne Mountain Air Force Station in Colorado Springs, Colorado

© Flickr / Airman Magazine

The Cheyenne complex includes 15 three-story underground buildings; each is buffered by a 25-ton blast door. The buildings are mounted on massive springs to absorb the shock from a possible nuclear blast, while the entrance is protected by a vault-like door several feet thick.

The two 23-ton blast doors at the entrance inside the Cheyenne Mountain Complex are made of steel and can take up to 20 seconds to close with the assistance of hydraulics

© Flickr / Airman Magazine

The bunker is home to more than 1,000 personnel, and it is able to operate as an underground town for months with its own supplies of fresh water and food.

Two large screens light up the alternate command and control center in the Cheyenne Mountain Complex in Colorado

© Flickr / Airman Magazine

The complex is 2,000 feet below the granite surface of Cheyenne Mountain and designed to withstand a direct hit by a 30 megaton nuclear explosion. It was shut down in 2006, but re-opened in 2015.

Lt. Gen Daniel R. Hokanson, the U.S. North Command deputy commander, and his staff walk into the Cheyenne Mountain Complex at Cheyenne Air Station, Colorado

© Flickr / Airman Magazine

A joint US and Canadian command, NORAD was formed back in the 1960s in order to scan the skies for threats emanating from missiles, aircraft and space objects.