For all you interested in earth science, Yellowstone, or those who've read Harry Turtledove's disasterporn (actually, it wasn't-it was rather factual and a good read) Supervolcano series....
An incredible place to visit; and potentially dangerous in many ways, from geysers to thermal pools to grizzly bears. Nature can be quite unforgiving, yet spectacularly beautiful.
@arronpaul46, yes, I believe that happened late last year, or early this year. His body just basically dissolved. You can't dick around in those places.
Impending doom or not, Yellowstone is very stunning.
I'm going there this summer.