Big Messy Rock Piles surrounded by smaller ones

Continuing from where I left off here, I had just pushed my way through the mountain laurel and fallen branches, sniffing out small ground piles when I came up to a nice "mound" in the woods. Nicer anyway than the previous "big messy" rock pile but, like it, surrounded by smaller outliers. In retrospect, I should have looked for a piece of quartz on this one but instead I was looking for "hollows" which I take to be collapsed inner cysts but which other people speculate could have been a place to sit - interpreting the whole pile to be a prayer seat. I did not have much luck photo'ing any hollows but they were there and I also tried capturing them with a video:

These piles are on a large hill with slopes facing towards Mt. Wachusett towards the southwest. But this site with the "big messy" piles actually is facing north - a rare direction to look out over. Reviewing the video, it is still hard to see what I am calling "hollows". But watching it a couple of times, I do start seeing some structure: there are rocks that poke up through the dead leaves that provide outlines - after a fashion. Around the first "hollow", notice a curved line of such rocks and along the left side of the second "hollow" there is a straighter line of such rocks. Can you see what I am talking about? [If the first, left-hand hollow was a place for a person to sit, then the right-hand one would have seated between five and ten people.]

I noticed more site layout around this second large pile. Here is a kind of alignment of rock piles: There were also many small nondescript piles, perhaps worth more attention:
Also some of the piles were larger and better preserved. Look at this one:closer: Here are some others: [Love that sense of pushing through the laurel to see these for the first time].

These piles have the characteristic feature of one side being slightly flat and vertical, a characteristic I think of as having an astronomical function. Whatever its purpose, the presence of such piles here, near these mounds with hollows, shows exactly the same site structure as many of the sites I have been finding this spring and calling the "Wachusett Tradition". It is the most common type of site I see out here west of the Nashua River.

Gosh, I forgot to mention, there was another little pocket of rock piles that seemed to have a larger "manitou stone"-shaped rock sticking out the top: