Marblehead Lighthouse, Marblehead, Ohio Lake Erie
Marblehead Lighthouse in Marblehead, Ohio, United States, is the oldest lighthouse in continuous operation on the United States side of the Great Lakes. It has guided sailors safely along the rocky shores of Marblehead Peninsula since 1822, and is an active aid to navigation. In 2012 an LED light was installed. Its green signal flashes every six seconds and is visible for 11 nautical miles (20 km; 13 mi). The distinctive green distinguishes the lighthouse signal from white lights coming from air beacons.