V-Shaped Piles - Revisiting the grid at Patch Hill Boxborough

There are about thirty little rock piles on about 1/4 acre of land enclosed by stone walls. They give the impression of being in lines and evenly spaced:Some of them are nicely built up like "biscuits":Many of them have a "V" or triangular shape, as seen from above (including the "biscuit" above). Look carefully at the how each of these has two straight sides coming together in a corner:And this nice one with a piece of quartz at the tip of the "V":One more: A very deliberate shape.

I wanted to know if there was some viewing location for the "grid". Actually there seemed to be two distinct clusters of piles: one visible from a low knoll, the others visible from a messy central area:One more look, re-enforces the "grid" idea: