The Lighthouse Of Island Sant'Andrea, Gallipoli, Apulia, Italy. Stock Photography

A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors they also assist in aerial navigation. Isola Sant'Andrea Lighthouse, in Italian: Faro dell'Isola di Sant'Andrea is an active lighthouse located on a flat islet, the Isola Sant'Andrea, positioned at 1.5 km from Gallipoli on the Ionian Sea. The lighthouse was built in 1865 and consists of a white octagonal prism tower, 13 m high, with balcony and lantern, rising from a 2-storey white keeper's house. The lantern, painted in grey metallic, is positioned at 45 metres above sea level and emits two white flashes in a 10 seconds period, visible up to a distance of 35 km.