At a number of different sites I see what seems to be an aligment and what seems like a good place to sit - a high point of some kind - to look down along the alignment. But it does not work out exactly because the alignment runs just to the side of the place to sit. Thinking about it now, I remember a site in Sterling with faint stone walls (alighments) leading up to boulders (places to sit) but the lines missing the high point of the boulder; and I can think of another site or two where piles line up with a position on a knoll just to the side of the highpoint. Does one sit below the highpoint on the line or at the highpoint but to the side of the line? Obviously a pretty speculative and hypothetical question.
I was reminded of this the other day when I was exploring a stream valley in Bedford and came across a circle of stones on a slight rise of land in the midst of the wetland. It could have been a fire circle or maybe a prayer seat. There were two other rocks poking up on the surface (see red arrows in picture) and they lined up with the edge of the circle. So the line was tangent to the circle, and this seemed significant and made it seem more likely that this was a seat and not a fire ring.
So it was interesting to open a magazine [Ancient American] and come across this picture of earthworks in Wisconsin.
How about those long structures with alternating circles along a line? They say they are effigies.