A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses and used as an aid to navigation for maritime pilots at sea or on inland waterways.
Lighthouses mark dangerous coastlines, hazardous shoals, reefs, safe entries to harbors, and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and replacement by modern electronic navigational systems.
Lighthouse development accelerated in the 17th century with Britain's Trinity House constructing its first in 1609, and a national lighthouse services established in Denmark (1650). In the UK, the first Eddystone Lighthouse was lit in 1698, though its third incarnation was the most enduring, designed by John Smeaton and finished in 1759. As Britain became the dominant sea power, lighthouses constructed by the Stevenson family for the Northern Lighthouse Board began to appear in Scotland.
