So I continued up the hill heading northwest, crossed a small landing strip on top and came to an outcrop. I could see there was something on it and, as I looked around, there was evidence of rock piles. Here are some closeups:
And then there was a fine pile. Here is a view of it, facing back south towards the landing strip
Then once I got up to the very top: rock piles, evenly spaced in lines and gridlike:
These piles are visible from a boulder (behind and to the rear from the point of view of these piles) which I looked at later. Also I became aware of an interesting wall feature. Lets take a closer look at that wall.