At the north-eastern end of the Cotentin peninsula, Pointe de Barfleur and its Gatteville lighthouse signal the dangerous currents at the north-western limit of the Baie de Seine. At the lighthouse's side stands the first one, built in 1774 and converted into a semaphore. Some 27 people (6 keepers and their families) lived there until its electrification in 1893. It became automatic in 1984, and only one person monitors the electronic instruments. A second optic joins the first in case of intense fog, and the four beams have a range of 37 miles (60 km).