Castillo de San Marcos, 1 Castillo Drive, Saint Augustine, St. Johns County, FL

Significance: The star fort and its moat and outworks were built to protect Spanish territory in Florida from attacks by the English. Castillo de San Marcos is the oldest masonry fort in the continental U.S. It was the site of a British Garrison in the Revolutionary War, was acquired by the U.S. in 1819 and used as a military prison. The fort last saw action in the Spanish American War in 1898.
Unprocessed Field note material exists for this structure: FN-84
Survey number: HABS FL-17
Building/structure dates: 1672- 1695 Initial Construction
Building/structure dates: 1738- 1740 Subsequent Work
Building/structure dates: 1752- 1756 Subsequent Work
Building/structure dates: 1762 Subsequent Work
National Register of Historic Places NRIS Number: 66000062