> This is a picture I took right before it got really steep...
I set your picture side-by-side with mine with the Juniper (two above yours), and the right half of mine shows the same rocks as yours. You were just a dozen steps farther forward.
It was the steepest part of the climb. I think I did stay close to the wall, climbing blocky steps, in the left side of your pic.
> Any idea what this thing is?
To this day, that structure baffles me!
The gravelly sand on top had some charcoal remnants, so I guessed maybe it was an elevated stove area. But that log platform on the ground just did not make sense. I am totally puzzled.