Inside Wyoming's Nuclear Missile Silos

You can tour a few decommissioned or training missile silos in the US: https://www.afmissileers.org/Tour-a-Missile-Silo

I've been inside the trainer silo at Ellsworth Air Force Base as part of a visit to the South Dakota Air & Space Museum. It's a fascinating and eerie experience, especially because there is actually an inert missile still in the silo.