I would not have seen the first cluster of piles except I was poking around having a closer look at this short stretch of stone wall, from below:
and from above:
At a different spot (isolated, not in the blue triangle), what looked like a small fire place against a boulder:Also a random observation, four or more rocks in a line - too many to be random:
At the top of the triangle, some slightly larger piles are up in the woods at the edge of the open field.Some faintly rectangular:
View towards the field:
Not only were some piles here faintly rectangular, some of them also had a faint hollow in the middle.
Perhaps a bit of vertical siding.
And also, nearby, another short stretch of wall:
Further downhill, another site (at the right hand corner of the triangle on the map):
Hidden in the bushes and hidden in the snow.