Next to a swamp behind a school in Littleton, MA

by PWAX
I found these small supported piles at one spot near the edge of a wetland:
(view to the north)
(view west)The site is pretty badly damaged with some piles almost totally buried. The wetland is beyond the wall. These are a bit effigy-like but who knows - with the damage?
Then I followed the edge of the wetland, across a different wall, and found this very large pile:
In this view there is a hint of inner structure where the trees are growing from the middle of the pile.Are these piles from field clearing? The piles in the first cluster are delicate little structures so: no, they are not from a farm clearing. But it is harder to dismiss the possible farm relation to this big pile. But observe the size of the rocks to be large and relatively uniform. The hint of "inner chamber" structure is consistent with this being an old damaged mound - much like what we see in the hills of Leominster.

In the end, I guess the damage is what is farm related. One last piece of evidence. This picture of the large pile from a distance shows a small pile in the foreground made from the same sized rocks as the large pile. This indicates site structure.