Castillo de San Marcos

St. Augustine, St. Johns County

In 1672, the Spanish began construction of Castillo de San Marcos which stands today as the oldest masonry fort in the United States. The Castillo replaced rotting wooden forts that had long been the only system of defense for the people of St. Augustine. Most importantly, the Castillo was designed to be a powerful obstacle halting British advancement in North America. Construction of the Castillo was slow, taking 15 years to build the main portion of the fort and 24 to complete the entire structure. The effort proved to be valuable, as the Castillo held off a British siege in 1702. During the American Period, Chief Osceola was imprisoned there during the Second Seminole War. The Castillo was renamed Fort Marion during its occupation by U.S. forces during the Civil War. It was declared a national monument in 1924.


Did you know...

  • You can learn about the Castillo by exploring the casements and exhibits found within the 20.5 acre site.
  • Living historians provide historical weapons demonstrations and programs on the life and experiences of the fort and St. Augustine residents.
  • Just nearby you can explore the many historical buildings and museums in the nation’s oldest city, St. Augustine, over which the Castillo de San Marcos still stands guard.

Castillo de San Marcos Website

1 S Castillo Drive
St. Augustine, FL 32084