Star Gazers' Stone
Star Gazers' Stone located on Star Gazers' Farm near Embreeville, Pennsylvania, United States, marks the site of a temporary observatory established in January 1764 by Charles Mason and Jeremiah Dixon which they used in their survey of the Mason–Dixon line. The stone was placed by Mason and Dixon about 700 feet (213 m) north of the Harlan House, which was used as a base of operations by Mason and Dixon through the four-and-a-half-year-long survey.