Spanish Colonial Forts were military structures built by the Spanish Empire during the 16th to 18th centuries to protect their territories in the Americas and the Caribbean. These forts were strategically located near coastlines and trade routes to defend against pirates and rival nations. They often featured thick stone walls, bastions, and moats, showcasing advanced military architecture of the time. Many of these forts, such as Castillo de San Marcos in St. Augustine, Florida, and El Morro in San Juan, Puerto Rico, are now preserved as historical sites. They serve as reminders of the colonial era and the military strategies employed to secure Spanish interests in the New World.