Castillo de San Marcos

The Castillo de San Marcos is the oldest stone fortification in the continental United States and one of the most beloved landmarks of St. Augustine. Built of coquina from Anastasia Island, it succeeded nine wooden forts that had previously stood at the entrance to Matanzas Bay. In 1669, following Robert Searles’s attack on St. Augustine, Queen Regent Mariana of Spain ordered that stone fortifications be built to better protect this presidio from maritime attack.

Castillo Plan, 1697.

The Castillo was designed by engineer Ignacio Daza. The first stone was laid in October of 1672. Indigenous laborers as well as laborers brought over from Havana, Cuba built most of the Castillo. The first construction period lasted from 1672-1695. The fort was built with four bastions, a ravelin, and a glacis. Its moat was dry. In the 1730s, the casements (rooms) of the Castillo were given new vaulted ceilings.

The incredible nature of coquina meant that the Castillo de San Marcos would never be taken by force. Though it traded hands several times, this was done by treaties or receipts on slips of paper. The fort housed British troops during the American Revolution as the Treaty of Paris of 1763 ceded Florida to Great Britain.

Plano del Castillo de San Marcos en San Agustin de La Florida Oriental, 1817.

When Florida became an American Territory, the fort had fallen into disrepair. Americans called the Castillo Fort Marion after Francis Marion, a Revolutionary War hero from South Carolina. Congress appropriated funds to bolster this fortification, for it was still needed. The United States Army used this as a holding facility for American Indian prisoners in three separate periods. In the 1830s, Seminoles were held here, the 1870s saw Plains Indians held captive here, and the 1880s saw tents constructed on the terreplein to hold Apache prisoners.

Today the Castillo de San Marcos, so renamed, is run by the National Park Service and open for tours seven days a week.

Castillo de San Marcos.