St. Augustine Light, at the north end of Anastasia Island, is the second lighthouse on a site used for coastal signaling since at least 1565. Florida’s first official lighthouse was established here in 1824, but shoreline erosion doomed that tower, which collapsed into the sea in 1880 after the present lighthouse entered service in 1874. Built from 1871 to 1874, the 165-foot tower originally used a first-order Fresnel lens and remained tied to national events, from Civil War efforts to hinder Union navigation to World War II coastal watch duty. Now maintained by the St. Augustine Lighthouse & Maritime Museum, it remains an active aid to navigation and a major preservation site.