After the caves, we went to see this geologically active crater,, a huge hole in the ground near the top of one mountain, bubbling over with dark grey mud & spewing out huge steam clouds of sulpher. Ohh! It stunk! But was amazing at the same time. I took a 15 second video- which is really the only thing that does it justice. It sounds like a big pot of spaghetti sauce boiling… on a bigger scale. At first I thought,, eh- it’s just a crater. But I’m glad I went. I’ve never been to Yosemite or seen Old Faithful,, but seems comparable. Too bad sulpher stinks so bad!