LighthouseAn aid for navigation and pilotage at sea, a lighthouse is a tower building or framework sending out light from a system of lamps and lenses or, in older times, from a fire. Lighthouses are used to mark dangerous coastlines, hazardous shoals away from the coast, and safe entries to harbors and can also assist in aerial navigation. Because of modern navigational aids, the number of operational lighthouses has declined to less than 1,500 worldwide. |
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