Fort Matanzas National Monument
Such an approach avoided St. Augustine's primary defense system, centered at Castillo de San Marcos.[7] Convicts, slaves, and troops from Cuba were used as labor to erect the structure, which was sited on present-day Rattlesnake Island[8] and had a commanding position over Matanzas Inlet.[13] The marshy terrain was stabilized by a foundation of pine pilings[7][14] to accommodate a building 50 feet (15 m) long on each side with a 30-foot (9.1 m) high tower.The Fort Matanzas National Monument Headquarters and Visitor Center, located at 8635 A1A about 15 miles (24 km) south of St. Augustine, Florida, was built in 1936.Located on Anastasia Island, it services the Fort Matanzas National Monument, a five-minute boat ride away.[26] Additional designed features include flagstone walkways and sidewalks, an exterior staircase, a retaining wall, parking areas and roads and curbs.