On top of this hill is a foundation for a small building, which would have been surrounded by these structures. This site is about 1000 feet south of the boulders aligned to winter solstice that I showed 12/22/2011. The bearing would be about 155 degrees, but since I don't know the vantage point for winter solstice, I can't be precise.
Here are photos taken at this strange site on a cold winter afternoon. Next to the trail uphill from the main road is this slab resting against a boulder, which was produced by quarrying.
A wash tub rests in front of another propped boulder.
Here is a view of this hill from the west, before the area was overgrown. These hills crowned with boulders must have been an impressive sight in the late afternoon sun. In the foreground, a propped boulder stands outside a wall. The area at the foot of the hill is swamp. The pile of boulders is to the far right on the crest of the hill, and another collection of massive boulders is left of center. The winter solstice site is barely visible between these two landmarks.