Florida Historic Forts

Castillo de San Marcos in St. Augustine, begun in 1672, is the oldest surviving masonry fortress in the United States, and Fort Caroline National Memorial near Jacksonville recalls an earlier French colony of the sixteenth century.

The Fort Caroline memorial recalls the short-lived French presence in sixteenth century Florida and the three hundred colonists who left France to settle there, and it hosts the visitor center for the whole Timucuan Preserve; its mailing address is 12713 Fort Caroline Road in Jacksonville and the phone is 904-641-7155 (NPS Fort Caroline National Memorial).

The Castillo's stone walls went up after pirate raids, including one in 1668 by John Davis, led the Spanish governor to ask for a more permanent defense and the Spanish crown approved a stone fortress; construction began in 1672, with four bastions and coquina walls 30 feet high and 14 feet thick (NPS, Castillo de San Marcos). The Park Service says the fort was never captured in battle and was the only structure to survive the fire the English set in St. Augustine after an attack in 1702.

Castillo de San Marcos in St. Augustine, Florida, charges $15 for visitors 16 and older, good for seven consecutive days, and children 15 and under enter free with an adult.

The Florida park does not take cash; only credit and debit cards are accepted, and an annual pass costs $45 (NPS Castillo fees and passes). It is open every day except Thanksgiving and Christmas, with first admission at 9:00 a.m., last admission at 5:00 p.m., and all visitors out by 5:15 p.m. (NPS Castillo operating hours). The park's mailing address is 1 South Castillo Drive, and the phone is 904 829-6506.

For a quieter visit to the Atlantic coast fort, the Park Service says attendance is lowest from mid-September through mid-November (NPS Castillo hours). After the United States took Florida, the fort was renamed Fort Marion and became a storage facility for military supplies until the Second Seminole War began in 1835 (NPS, Castillo de San Marcos).

Fort Matanzas, south of St. Augustine, is reached by a free National Park Service ferry, and riders of all ages need a free boarding pass from the Fort Matanzas Visitor Center.

All areas of the park are free, including the ferry, but the boarding pass must come from the Fort Matanzas Visitor Center, not the St. Augustine city visitor center, and the park uses a timed entry system (NPS Fort Matanzas fees). The park's mailing address is 8635 A1A South, and the phone is 904 471-0116.

The fort is a coquina watchtower completed in 1742 to guard the southern approach to St. Augustine, and the monument also protects about 300 acres of Florida coastal dunes, marsh and maritime forest (NPS Fort Matanzas National Monument). The Park Service explains why it was built: the British had unsuccessfully besieged St. Augustine in 1702 and 1740, and Governor Montiano expected them to try the unguarded Matanzas Inlet next, so he ordered a fort to guard the southern approaches (NPS Fort Matanzas history).

Fort Jefferson in the Dry Tortugas and Fort Pickens on Santa Rosa Island belong to the Third System of U.S. coastal forts, and Fort Barrancas added protection at the entrance to Pensacola Bay.

Fort Jefferson was nearly thirty years in the making, from 1846 to 1875, and was never finished or fully armed; the Park Service calls it one of the largest forts ever built and a link in the Third System chain of coastal forts that stretched from Maine to California (NPS Fort Jefferson). Entry to Dry Tortugas National Park is $15 per person for seven consecutive days, visitors 15 and under are exempt, and ferry tickets already include it; private boaters and private seaplane visitors buy a digital pass in advance through Recreation.gov (NPS Dry Tortugas fees).

The United States Army built Fort Pickens in the 1800s to help defend the Gulf Coast; the Third System was extended to Pensacola Bay in 1821, and from Santa Rosa Island the fort worked with Fort McRee on Perdido Key to guard the bay entrance, while Fort Barrancas and the Spanish Water Battery added more protection (NPS Fort Pickens). The Park Service notes that the Army forced enslaved Black men to build and later repair Fort Pickens, that it became a destination on the Underground Railroad during the Civil War and after, and that Chiricahua Apache prisoners of war, including Geronimo, labored there for one and a half years after the Apache Wars. Fort Pickens joined Gulf Islands National Seashore in 1971.

Five National Park Service sites in Florida preserve historic forts, and Fort Matanzas, ferry included, is free to visit.

Castillo de San Marcos accepts only credit and debit cards (NPS Castillo fees), while at Dry Tortugas the seaplane collects the entrance fee before departing Key West (NPS Dry Tortugas fees).

The State Library of Florida keeps a Forts in Florida guide to books, journal articles and maps, most of them available through interlibrary loan or from its circulating collection.

The guide's journal articles cover posts such as Fort Brooke from 1824 to 1836, Fort Foster as a Second Seminole War fort, Fort Gatlin, Fort Dade, Fort Mitchell in the Alachua Country and Fort Myers in the Civil War, and its books include studies of Fort George in Pensacola, Fort Mose, Fort Jefferson and the Chiricahua Apache prisoners of war (State Library of Florida, Forts in Florida). It also lists articles on Fort Marion, the American name for Castillo de San Marcos, during the Seminole War of 1835 to 1842.

The Castillo itself served in those wars: by 1842 Army engineers had added a water battery and furnace and refilled the moat, and the fort then served as an active defensive fortification during the Seminole and Western Indian wars (NPS, Castillo de San Marcos). The Seminole history and Civil War guides in the history section explain the wars these forts served.

Last verified: October 18, 2026, by re-reading the National Park Service pages for Castillo de San Marcos, Fort Matanzas, Fort Jefferson and Dry Tortugas fees, Fort Pickens and Fort Caroline, and the State Library of Florida forts bibliography.