What underground nuclear bunker near Blue Ridge Summit, Pennsylvania known as "underground Pentagon" became operational in 1966?
Raven Rock Mountain Complex The Raven Rock Mountain Complex (RRMC) is an American military installation with an underground nuclear bunker near Blue Ridge Summit, Pennsylvania, at Raven Rock Mountain that has been called an "underground Pentagon." The bunker has emergency operations centers for the United States Army, Navy, and Air Force. Along with Mount Weather Emergency Operations Center in Virginia and the Cheyenne Mountain Complex in Colorado, it formed the core bunker complexes for the US Continuity of Government plan during the Cold War to survive a nuclear attack.
Underground Great Wall of China The Underground Great Wall of China is the informal name for the vast system of underground tunnels China uses to store and transport mobile intercontinental ballistic missiles. Due to the immense amount of secrecy surrounding the tunnels, not much information about them is publicly available however it is believed that the tunnels allow for mobile ICBMs to be shuttled around to different silos and/or stored in reinforced underground bunkers. This greatly enhances the ICBMs chance of survival in a direct nuclear strike, which enables their use in a second strike unlike ICBMs based in static nuclear silos which generally do not survive a direct nuclear attack.