When I saw that brick red stone in Normans photos of Foxborough I remembered that there was also one in a 'prayer seat' here. I knew this rock was odd, it stood out, I have not found another one around here. I knew it had some kind of connection to this seat here. Also, the shape of the Foxborough 'prayer seat' area is exactly like the one I have here. (A large enclosed area with the seat at the far end) I am unable to take a complete photo of the whole seat because much of it is under heavy debris and leaf mould but I can distinctly see the same shaped outline!
I was very excited to have seen that link to one of my local piles!