 We're looking at Sunset Crater, a volcano that erupted almost a thousand years ago, it's primarily a cinder cone, so when it was erupting, it was sort of spitting out little pieces like a pot of spaghetti sauce, bubbling and throwing things. Those little pieces, we can actually see similar pieces from either that one or a different eruption here. And we've been walking on them, and they're not terribly pleasant for walking on, but you can build a pile out of stuff like this. There's probably lava flows helping to hold that one up. A little more oxidized late in the eruption, and so you get that pretty red around the top that gives the Sunset Crater name.