The oldest masonry fort in the continental United States, the Castillo de San Marcos is a large Spanish stone fortress built to protect and defend Spain’s claims in the New World. It’s a National Monument and, at over 315 years old, it’s the oldest structure in the entire city! At the fort you will find plenty to explore, from the numerous rooms that once housed soldiers and prisoners of every era, to the large interior courtyard and gun deck which offers a great view of the city. This is a magnificent attraction for the whole family to learn about the nation's oldest city. Re-enactments, cannon firings, and weaponry demonstrations are held on a regular basis.

A brief history of the fort:

Construction began on the Castillo de San Marcos in 1672 and lasted 23 years, until 1695. Many Spanish forts preceded the Castillo, however, this one made of coquina was impenetrable to enemy attack and was fire resistant. The fort came under fire for the first time in 1702. British forces, led by General Moore, burned the city but could not penetrate the Castillo’s walls. Subsequent attacks in 1728 and 1740 yielded similar results, and the British were never able to take the city of St. Augustine by force. In 1763 however, Florida became a British colony with signing of the Treaty of Paris, this began a 20-year period of English rule. Used as a military prison during the Revolutionary War, and at one time it held three signers of the Declaration of Independence within its walls.

At the end of the Revolutionary War, Florida was returned to Spain in 1784 until Florida became a United States Territory in 1821. The American’s called the Castillo, Fort Marion, honoring a Revolutionary Patriot from the Carolinas, General Frances Marion. The U.S. Government used Fort Marion as a prison for Native Americans in the late 1800’s. Natives from both Florida and the Great Plains were held at the fort during this time.

The fort was officially taken off the active list of fortifications in 1900 and it was preserved and recognized as a National Monument in 1924. Congress renamed the fort in 1942, reverting it to the Spanish name Castillo de San Marcos. At over 315 years old, the fort is a lasting landmark of Seventeenth Century St. Augustine.