This was an amazing location: Canyon X in Arizona. This location is on provate property and requires a giude and a group of us hired one.
I think this slot canyon is deeper than Antelope Canyon, but I am not sure. It seemed much darker and that could be due to different geological formations, but again, I am not sure.
It was tough to process and it went very blue at the bottom and warm at the top, so I added a B&W adjustment layer and dialed some color out and painted back in the warm colored slit.