Drawing of the Lighthouse of Alexandria, on the island of Pharos

The Roman lighthouse at Dover Castle.

Lighthouse "El Faro", Maspalomas, Gran Canaria. A lighthouse is a tower, building or, framework designed to emit light from a system of lamps and lenses or, in older times, from a fire and used as an aid to navigation and to pilots at sea. Lighthouses are used to mark dangerous coastlines, hazardous shoals, safe entries to harbors and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to replacement by modern electronic navigational aids.