The Castillo de San Marcos, built by the Spanish between 1672 and 1695 of coquina quarried nearby, is the oldest masonry fortification in the continental United States, and it survived the destruction of the city by British forces in 1702; the National Park Service runs it. South of the city, Fort Matanzas is a coquina watchtower completed in 1742 that guarded the southern approach to the town, and it is a national monument too.
01Castillo de San Marcos
St. Johns County. Spain began the Castillo in 1672 and finished it in 1695, after wooden forts had burned or rotted through a century of trying. The material is coquina, a soft stone of shells bonded together, quarried at King's Quarry on Anastasia Island and ferried across Matanzas Bay.
Open the guide →02St. Augustine Historic District
St. Johns County. St. Augustine was founded by Spain in 1565, making it the oldest permanently settled European city on the mainland of North America north of Mexico. What the historic district protects is not only the buildings but the plan itself.
Open the guide →03Fort Matanzas National Monument
St. Johns County. Matanzas means slaughters in Spanish, and the inlet got the name in 1565 when Spanish forces under Menendez executed Jean Ribault and his shipwrecked French Huguenots there. Spain built this tower in 1742 to stop anyone using the inlet as a back way to St. Augustine, after Oglethorpe's forces had shown the weakness.
Open the guide →04St. Augustine Lighthouse & Maritime Museum
St. Johns County. The tower went up in 1874 and the keepers' house followed in 1876, and both stand at 100 Red Cox Drive on Anastasia Island. Climbing it means 219 steps up a spiral staircase to a gallery with a view over the whole of St. Augustine, the inlet and the Atlantic.
Open the guide →05Lightner Museum
St. Johns County. Flagler commissioned the Alcazar Hotel in 1887 to hold the overflow of wealthy visitors coming south on his railway. Carrere and Hastings designed it in Spanish Renaissance Revival style and built it of poured concrete, which made it among the earliest poured concrete buildings anywhere.
Open the guide →06Flagler College
St. Johns County. Henry Flagler made his money at Standard Oil and spent a good deal of it on Florida. The Hotel Ponce de Leon opened on January 10, 1888, as the grandest winter resort in the state, designed by the New York firm Carrere and Hastings as their first major commission.
Open the guide →07Fountain of Youth Archaeological Park
St. Johns County. Two things are true about this place at once, and the park is worth visiting because of both. The legend is that Ponce de Leon landed here in 1513 and found a spring.
Open the guide →08St. Johns County
Population 306,934. Typical home sale price $516,543 in the three months ending June 2026; typical condo $305,000 in May 2026. Median household income $109,839; 21.1% of residents are 65 or older. (Source: Redfin; U.S. Census Bureau, American Community Survey, published January 2026)
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