Oldest masonry fort in the U.S., built by the Spanish (1672–95) to protect St. Augustine
St. Augustine was founded by the Spanish in 1565. Over the next 100 years, the city was defended by 9 wooden fortsAfter the 1668 attack of the English pirate  Searle, it was decided by the Queen Regent of Spain, Mariana, that a masonry fort be built to protect the cityOct. 1672 construction began on the fort that would become the Castillo de San Marcos.The Castillo is a masonry star fort made of a stone called "coquina".......means "little shells". Ancient shells that have bonded together to form a type of stone similar to limestoneThe coquina was very effective at absorbing the impact of the shells, allowing very little damage to the walls during attack.