Woods West of Danforth Brook, Bolton MA

On a walk through the fall woods last weekend, I saw a small site next to a wetland and a few items on the high ground in there. For example, this stone U - blocked off:
It reminded me of the second photo here.

Here was a wedged rock under the yellow beech leaves:
The small site at a wetland consisted of a group of three or four rock piles around a disturbed area of soil.A closeup of one of the piles, (the right hand foreground pile above), with a piece of quartz:Seen from the other direction:
Notice the trenches in the dirt.

Nearby was this heavy rock structure: