圣奥古斯丁佛罗里达州马可堡国家纪念碑

tillo de San Marcos National Monument in St. Augustine, Florida, is the oldest masonry fort in the continental United States. The Spanish constructed the fort between 1672 and 1695 to protect their trade routes in Florida. Located on Matanzas Bay, this star-shaped fortress is built from coquina, a unique, durable, and shell-based stone that absorbed, rather than shattered, under cannon fire. The fort features four bastions, a large courtyard, and a moat. Today, the National Park Service administers the site, which offers self-guided tours of old prison rooms, reenactments with weapons, cannon firings, and panoramic views of the water from the gun deck.