Nike Missile Site SF-88
Mill Valley, CA
SF-88 is now a tourist attraction in the Golden Gate National Recreation Area, but back in the day, it was a launchpad designed to hurl Nike missiles at Soviet bombers. You can get up close and personal with those missiles on Thursdays, Fridays, or Saturdays between 12:30-3:30pm, or hold out for the open house with Nike vets on the first Saturday of each month. Regardless, the National Park Service would like to grimly remind you that the missiles were designed to protect military and industrial centers, not you!
The Brooklyn Bridge Bunker
New York, NY
When someone makes an "odd discovery" under a New York City bridge, it's usually an old bum on peyote who claims to be Rasputin. But in 2006, city workers uncovered something historically significant in the Brooklyn Bridge: a vault of emergency supplies. It clearly dated back to the Cold War, and was there to aid the survivors of a potential nuclear attack. The secret stash included an estimated 352,000 Civil Defense All-Purpose Survival Crackers, as well as water drums, medical supplies, paper blankets, and drugs like Dextran (which treats shock). The Departments of Transportation and Health & Mental Hygiene took everything away, though, so sadly you can't go bridge-cruising for '50s survival crackers.