Dating in groton carbon dating million years
It was named in honor of one of the original Selectmen, Dean Winthrop, who was born in Groton, Suffolk County, England.
In the same general area there is a group of nineteen cairns built on the ground.
The archaeologist Ken Feder notes that unlike European stone circles the stones are recumbent and not upright and identifies it as a bark mill used to extract tannin for leather making.
Walking in a circle animals would pull the mill wheel between the double circle of stones." The origin and meaning of the name is uncertain.
The outermost ring is made up of twelve stones worked to be curved.
Archaeologists who have studied it consider it to have been a mill.