Going in the Newbury Land in Concord next to Lowell Rd. there is a trail to the left that becomes a wide trail through the woods. Somewhere a little below the cross-hair on the map fragment, after 100 yards or so on the trail, there is a nice rock pile on the left:
Other views:A split rock a few feet away:With reference to my official topo maps at home, I see that there are a few more rock piles across the "gully" to the southeast from here but I did not go in that direction, this time.
I went further east, deeper in the woods, to the origins of that gully. Here is a spring with two small rock piles visible:Closeup:This gives a good feel for what a spring would have been like around here, back when.