Swamp Piles in Lincoln, MA

Like any sane mammal I want to stay near home on a cold day, and it takes this kind of circumstance to get me to want to explore in Lincoln - very near home - but Sunday it was 17 F with a bit of wind, so I went to a place called the Roger's Land which is between Brooks Rd and Sunnyside Ln in Lincoln. Stepped into the woods and there was a rock pile.
These are the ones that appear one-at-a-time or in small clusters where water comes out of the ground.Another view with a 2nd pile in the background:Closeup of that pile:
And nearby, a split-filled rock:Another scene. A spring with several structures:Some "gap"-type structures:Another split-filled rock:These were all in a small portion of the overall conservation land, just as you enter from the east from Brooks Rd.