30 Secret Underground Places in America Hidden From the Public

What if entire cities were buried beneath your feet — and no one told you? From a secret government bunker built to survive nuclear war, to a hotel room with zero light and zero sound 220 feet underground, these are 30 of the most shocking hidden underground places in America that most people will never see. Some were built for survival. Some were forgotten for decades. And some the government still doesn't want you to know about. Watch until the end — number 7 will change the way you look at city sidewalks forever.