Crossing a dry moat, this drawbridge was the only way into the Castillo.
Photo: NPS Photo
About
Built by the Spanish in St. Augustine to defend Florida and the Atlantic trade route, Castillo de San Marcos National Monument preserves the oldest masonry fortification in the continental United States and interprets more than 450 years of cultural intersections.
Activities
Living HistoryHistoric Weapons DemonstrationJunior Ranger ProgramPark Film
Directions
On State Route A1A overlooking Matanzas Bay in the heart of the historic district of Saint Augustine, the Castillo is approximately a five mile drive from Interstate 95.
Get directions →Weather
St. Augustine has a semi-tropical climate with over 300 days of sunshine each year. Summers (May-September) are hot, bright, and humid with afternoon thunderstorms common. Temperatures range from the lower 70s to the mid 90s F. Spring (March-mid-May) and Autumn (October-late November) can be pleasant with temperatures ranging from the upper 50s into the 80s F. The Winter months (December-March) are usually dry. Temperatures can be cool ranging from the upper 30s through the 60sF.
News
Sep 28, 2026
Volunteer Fair at the Waterworks Offers Opportunities at Castillo de San Marcos
Castillo de San Marcos National Monument invites the public to attend a volunteer fair on Oct. 3 from 10 a.m. to 4 p.m. at The Waterworks, 184 San Marco Ave.
Sep 1, 2026
Castillo de San Marcos and Fort Matanzas National Monuments Welcome New Superintendent
The National Park Service has selected Angelita Alvino as the new superintendent of Castillo de San Marcos and Fort Matanzas National Monuments. Alvino has served as superintendent of the national parks of St. Croix for nearly five years and brings more than 25 years of NPS experience. She started her official role as superintendent on Aug. 23.
Jul 8, 2026
Castillo Seawall Project Begins in July
On July 27, Castillo de San Marcos National Monument will begin mobilizing for construction to replace, raise and rehabilitate the park’s failing seawalls and protect the historic fort and the broader St. Augustine community. Visitor access to the historic fort will be maintained throughout this project, which is expected to take approximately 18 months. Some areas on the fort grounds will be closed to ensure public safety during construction.