Fort Independence (Castle Island) - 19th-century granite fort

Fort Independence on Castle Island in South Boston is a granite coastal fortification whose current structure was built between 1833 and 1851 on a site used for coastal defense since the 17th century. The fort's dry moat, bastions, and casemates exemplify 19th-century US coastal fort construction and it remained part of Boston Harbor defenses into the 20th century. Today the fort is managed as a historic site and is one of the older surviving federally related coastal defense works in New England.