A pretty little marker pile site in Princeton MA

I drove out to Princeton, to see what it was like south of Mt. Wachusett. I found a nice little marker pile site near Houghton Rd. Light and shadow made it hard to get decent photos, this comes closeWe see nice small vertical sided piles, evenly spaced and in lines, V-shaped:Note the large rock in the background, seems to be incorporated into the pattern:Another nice rock pile (many were broken down, but I am showing the nice ones). It is hard to show how they are spaced and in lines. Here is an attempt:The "spacing" is such that the distance from the 2nd to the 3rd pile is about twice the distance from the first to the second. Note the position of the larger boulder to the right of the line of piles, and note the vertical sides of the piles, and how they are oriented almost perpendicular to the direction between the piles.

This location was to the side of a scooped out hill, on a shoulder at the edge of a wetland:
The wetland is to the left in the above, which is taken facing north. The structures seemed to continue out into the wet area a bit, so I walked in that direction a few yards.To me this was a pretty little site, compact and with well preserved rock piles. But the features are somewhat standardized and are familiar. When I went into the wetland a bit here was something I have not seen before, at least not just like this:
The water is coming up out of the ground right in that crack between the rocks, and the mossy rocks in the foreground seem to inseminate the crack, in a suggestive way. I believe this is a deliberate structure, especially since it is at the edge of the marker pile site.

Update: This is the Foresteire Edmund and Priscilla conservation land.