The Bell Rock Lighthouse, off the coast of Angus, Scotland, is the world’s oldest surviving sea-washed lighthouse. It was built between 1807 and 1810 by Robert Stevenson on the Bell Rock (also known as Inchcape) in the North Sea, 18 km east of the Firth of Tay. Standing 35 meters tall, its light is visible from 35 statute miles (56 km) inland.
Before the construction of the lighthouse, the rock had caused many shipwrecks because, except for a few hours a day at low tide, it lies just below the surface of the sea. By the turn of the 19th century, it was estimated that, in a typical winter, as many as six ships were wrecked on the rock. (In one storm, seventy ships had been lost off the east coast of Scotland.)
The masonry work on which the lighthouse rests was constructed to such a high standard that it has not been replaced or adapted in 200 years. The lamps and reflectors were replaced in 1843; the original ones are now in the lighthouse at Cape Bonavista, Newfoundland, where they are currently on display. The working of the lighthouse has been automated since 1988.
The lighthouse previously operated in tandem with a shore station, the Bell Rock Signal Tower, built in 1813 at the mouth of Arbroath harbor. Today this building houses the Signal Tower Museum, a visitor center that offers a detailed history of the lighthouse.
Because of the engineering challenges that were overcome to build the lighthouse, it has been described as one of the Seven Wonders of the Industrial World.
According to Wikipedia