Sombrero Key Light stands on an exposed reef offshore from Vaca Key at Marathon in the Florida Keys, where a small island once shown on charts had largely eroded away by the late 19th century. Placed in service in 1858, the lighthouse rises 142 feet on iron pilings and is the tallest in the Florida Keys. Its red cast-iron skeletal tower, lower working platform, and upper keepers’ quarters were designed for the demands of an offshore station. Automated in 1960 and deactivated in 2015, it served navigation for more than 150 years and remains a distinctive historic structure in the Keys.