This is the infuriatingly mysterious Barnes/Vinal tomb in Scituate, Mass. It is across the street from the Barnes ancestral home where my family lived when I was really young. My older siblings all played in the woods around it, and were lucky enough to be able to explore inside. My brother tells me that there was nothing left inside when it was bricked up sometime in the mid-1900s.
The only printed reference to a burial here that I could locate is that of Polly (Vinal) Barnes (1784-1868), for whom I am named. The reference is made in a newspaper article about 35 years after her death, and says she was the last to be entombed there. I have to assume that her husband, Joseph Barnes is also there beside her, along with other relatives. I just wonder if some of them aren't also buried in the area around the tomb, since it is marked off.