"The Sharpner's Pond Anti-Ballistic Missile Site is a location in North Andover, Massachusetts which was designed to be the site of a Perimeter Acquisition Radar for the Sentinel system. It consists of the excavation for the radar and an underground power plant, which is now a pond."@en . . . . "Sharpner's Pond Anti-Ballistic Missile Site"@en . . . . "The Sharpner's Pond Anti-Ballistic Missile Site is a location in North Andover, Massachusetts which was designed to be the site of a Perimeter Acquisition Radar for the Sentinel system. It consists of the excavation for the radar and an underground power plant, which is now a pond."@en .