6000 years ago there was some volcanic activity in central Idaho. The earth sent some lava to the top and all sorts of things happened, caves were formed, little volcanoes were made and the earth got all crusty. This turned out to be a pretty good park, not too many people were there, the rangers were helpful, I liked it so much I stayed the night at the campground.
I did a little bit of night hiking which was cool, I was all alone with the volcanoes. Something you probably don't know about me is that I have a big problem with claustrophobia. Hence, most types of spelunking for me is out of the question. I hate this about myself but there is nothing I can do about it. Fortunately, a few of the caves available were the size of Fred Flinstone's church, so I was okay especially since there was a lot of sunlight and openings.