Broken down prayer seat?

Exploring northeast of Rocky Hill in southern Groton, found a curious broken down stone structure built against a boulder. [I browsed around this blog's archives and found a reader already sent photos of this several years ago. Click here.] Here are a couple of views I took:
In the woods on the other side of the road, south of 119, there is a very high-backed prayer seat like structure, with see-through stonework. I cannot find if that has been posted before. Anyway, this was somewhat reminiscent of that and perhaps it was the style around these parts. I should add that I know one more of these, in the saddle between summits on Millstone Hill, which is also not too far from here.