Castillo de San Marcos
Castillo de San Marcos, on Matanzas Bay
Welcome to St. Augustine, and to the Castillo de San Marcos, the oldest masonry fort in the continental United States. Spanish Admiral Pedro Menéndez de Avilés founded the city in 1565. After Sir Francis Drake's attack in 1586, nine wooden forts followed.
Then in 1668, the English privateer Robert Searles raided the town and burned much of it, and Spain decided to build in stone. Construction began on October 2, 1672, to a design by the engineer Ignacio Daza, and the core of the fort was finished in 1695. It's built of coquina, a stone made of ancient shells bonded together, quarried across the bay on Anastasia Island. The star-shaped fort was attacked several times and besieged twice, in 1702 and 1740, but it was never taken by force.
It changed hands five times, always peacefully. Under U.S. control it served as a military prison for Native Americans, including the Seminole war chief Osceola and members of Geronimo's band. The fort's original name was restored by Congress in 1942.
Sources: en.wikipedia.org › Castillo_de_San_Marcos · wikidata.org › Q101094405