Fort Independence is a 19th-century granite fort, not an original colonial structure

Fort Independence on Castle Island occupies a site used for coastal defense since the 17th century, but the granite fort visible today was largely constructed and finished in the 19th century rather than being the original colonial-era structure. Visitors who assume the existing masonry dates to the Revolutionary War are seeing a later federal-period reconstruction built on the earlier fort's footprint. The site is open to the public as a historic landmark managed by state authorities.