If you have any interest in American history, and in particular, Cold War era history, you should take the time to tour the Minuteman Missile National Historical site. You can tour the underground missile launch facility. This is not the missile silos where the actual nuclear warheads were kept, but it is the control facility for many of those silos. Absolutely fascinating for this baby-boomer. It's in west-central South Dakota, very near the Badlands National Park.
Minuteman Missile National Historical Site-Speak