B-427 Scorpion

Docked right next to the iconic RMS Queen Mary in Long Beach, this Soviet-era Foxtrot-class submarine lets you step inside a real Cold War vessel and experience the claustrophobic reality of life underwater. It's a genuinely surreal thing to crawl through — the cramped quarters, torpedo tubes, and original equipment make it feel like the crew just stepped out. Note that the submarine exhibit has had closures, so check current availability before you make the trip.