Image
Stargazers' Stone on the John Harlan or Stargazers' Farm, near Stargazers' Road and PA 162 near Embreeville, PA, 2013.
Credit: Charles Hardy III
Early in 1764 Mason and Dixon placed this stone 15 miles south of the Plumstead and Huddle house on Cedar Street in Philadelphia near present day Embreeville, PA. This they then used as their base point for plotting the boundary between Pennsylvania and Maryland. The name Stargazers' Stone comes from the astronomical observations they made at this site.