Antelope Canyon above.
I think I have seen pix of since I was a kid without knowing much about it. I remember reading, probably in the Audubon mag, as a kid about the many slot canyons and was very intrigued. They are spectacular. Antelope Canyon is a tourist trap now.
To my surprise, there is a slot canyon, or two, here but in different geology.
A reminder how it got that way.
Tons more on the web.