Lighthouse

A lighthouse is a fixed shore or offshore tower carrying a high-intensity light, and often a fog signal and radar beacon, marking a coastline, hazard, or landfall for mariners. Each shows a documented light characteristic (color, rhythm, period) and nominal range listed in the Admiralty List of Lights or the USCG Light List, letting a navigator identify it positively. Modern lighthouses use rotating optics or LED arrays; many are now automated and monitored remotely. Their positions and characteristics are charted and amended through Notices to Mariners.