A possible calender site on the Uxbridge/Douglas border

North of Rt 16 on the Uxbridge/Douglas border is a nice open woods. I walked in from Rt 16 on the east side of the brook and began trending uphill, thinking: going up to the top of the hill is a bad habit I acquired from Bruce McAleer and there is rarely anything at the top except a few hilltop sites in Harvard and Boxboro, and Henry's Hill in Framingham. I walked along and came to a valley between summits and a stone wall, and thought: I can go left or right, I'll go right further uphill. There were a few traces around, like this damaged pile:

A moment after turning further uphill, I saw a distant rock-on-rock and, as I came up to it, I was happy to see it was part of a sequence of rock piles:

A view from the side:

The even spacing is a characteristic of what I call "marker pile" sites - where the piles have the properties of "tic marks" dividing the horizon as would tic marks on a ruler. They were nice piles but a bit old:

 The telltale blaze of a piece of white quartz on some of them:

On the hilltop was a magnificent sight. 

A boulder with marker piles, marching along beside it...

… and extending to all the places where shadows from the boulder would be cast by a western sun or moon. Of course this is my fantasy construction for what is going on at this site. I do believe it is a type of sundial but it will take someone more systematic than me to go out and see where the shadows fall. Here are other views:

A few other things on the northwest shoulder:

I doubt many will visit this site but it is highly recommended for students of astronomy, because it is a natural location with regular features, waiting to be measured.