Horned Creature and other possible effigies with quartz, other piles, near Parker Village

I walked some more in the woods near Parker Village, Westford, MA and thought I saw something burial like and a few broken down piles. The quartz in this one...
...caught my eye:
Then I crossed a wall into a large wall enclosed rectangle/parallelogram with perhaps 50 rock piles scattered around. This one was still pretty intact:
But the real gem was this "Horned Creature" that I showed a little video of before (here). I have to show what I can of this since it is the best example I have seen.
Here is the front view. The "head" is quite symmetric as is the pile.
Here is the back view with a detail of the neck:
Look how the pile thins down in the "neck". By the way this creature is facing roughly west.

Now let's take a look at the pile that is visible in the background three pictures ago. It also has some symmetry and a piece of quartz. It seems to be following the horned creature.
If that is another "head" facing us, then this creature has quartz at its belly area rather than its neck. Here is the detail:
There were certainly plenty of other piles here also worth studying more than I did. Here a scene looking west:
I have to run. This ends the marathon site reporting - I am caught up.