This census-designated place first settled in 1623 is home to a defensive fortification built at the mouth of what river?
Kittery Point, Maine:  Located beside the Atlantic Ocean, it is home to Fort McClary State Historic Site, and Fort Foster Park on Gerrish Island. Fort McClary: Fort McClary is a former defensive fortification of the United States military located along the southern coast of Maine at Kittery Point. Fort McClary:  Built at the mouth of the Piscataqua River, it was used primarily throughout the 19th century to protect approaches to the harbor of Portsmouth, New Hampshire, and the U.S. naval shipyard.
i don't know