Castillo de San Marcos National Monument Tours and Activities

St. Augustine’s Castillo de San Marcos National Monument is the oldest masonry fort in the United States and the only intact 17th-century fort. Constructed by the Spanish in 1672 to protect their New World territories, it eventually passed to the British and Americans, and it played a crucial role in the Civil and Spanish–American wars.

Now maintained by the National Park Service, the complex occupies 2.5 acres (1 hectare) in downtown St. Augustine. The structure was made from a stone called coquina, which is Spanish for “little shells,” and you can still see this strong material made of bonded ancient shells when you examine the fort’s walls.

You can visit Castillo de San Marcos independently or as part of a guided tour, which will help give context to this important historical site—where America began. The fort is a stop on St. Augustine hop-on hop-off trolley tours, and you can even admire it from the air during a helicopter tour.

 

The Castillo de San Marcos is open daily from 8:45am to 5pm, except Thanksgiving and Christmas. Crowds are thinnest from mid-September through late November, while peak season is June through Labor Day—especially during summer and holidays. Note that summer is also a very hot time to visit, even in the morning; spring and fall offer milder temperatures.

The narrowest street in the United States is in St. Augustine: Treasury Street, measuring 7 feet wide. It was built to be wide enough for two men to transport chests of gold to ships docked at the waterfront, reducing the likelihood that they would be robbed by carriages passing by.