What is Lighthouse?
[[File:Faro Les Éclaireurs, Ushuaia 11.JPG|thumb|Lighthouse at the end of the world in Ushuaia, [[Argentina]].]] [[File:Italy-Lignano-old-lighthouse-2001.jpg|thumb|lighthouse in Lignano (Italy)]] A '''lighthouse''' is a tall building that sends out [[light]] for use in [[navigation]]. Lighthouses are built on the [[coast]] of an [[ocean]] or [[lake]]. The lighthouse protects [[ship]]s from crashing into shore, by sending the light out towards the [[sea]]. When [[sailor]]s see the light, they know to avoid hitting the shore. The light usually turns in a [[circle]] so that ships see a flashing light. The light is usually covered by a [[Fresnel lens]]. This lens enables the light to travel a far distance. One of the most famous lighthouses was the [[Lighthouse of Alexandria]]. It was on an [[island]] near the coast. That island was called ''Pharos''. Even today, in many languages, the word for ''lighthouse'' comes from the name of the island. Almost all lighthouses are automatic now. {{commonscat|Lighthouses}} {{stub}} [[Category:Lighthouses| ]]