Timeline

Heritage classified

Key figures

Origin and history

The Four Lighthouse, also known as the "Four d'Argenton Lighthouse", was built between 1869 and 1874 on a 25 m-diameter granite pit off the St. Lawrence Peninsula (Porspoder, Finistère). This lighthouse at sea, designed for sea staking, marks the separation between the Channel and the Atlantic Ocean. Its construction, supervised by the engineers Planchat, Léonce Reynaud and Victor Fenoux, was marked by extreme conditions: flooding waves, difficult access, and a fatal shipwreck in 1870 (three victims). The tower, 28 meters high, rests on a concrete and granite base, with an innovative shape for the era, favoring stability by mass. Inside, five floors house functional spaces (tank, kitchen, bedrooms, technical room), connected by a spiral staircase. The lantern, always equipped with its oil vapour optics, is a rare testimony of 19th century technology.

The lighthouse entered service on 15 March 1874, after five years of construction interrupted by winter storms. His story is punctuated by tragic accidents: in 1899, lightning struck him; In 1913, a guardian died intoxicated by gas oil fumes; In 1978, two sailors drowned during refuelling. Automatized in 1993, however, it maintains its historical system, including an oil vapour optic and an aerogenator installed in 2005 to complete the generators. Ranked a historic monument on April 20, 2017, the Four Lighthouse is famous for its spectacular waves, captured by photographers such as Philip Plisson, and its role in navigation between Leon's land and the abers.

Architecturally, the Four Lighthouse is distinguished by its granite structure and its base serving as a haven in good weather. A twin of the Black Stone Lighthouse, it illustrates a major technical development: the abandonment of the "trumpet" shape in favour of a massive tower ensuring stability. The plans at the National Archives (1870–1905) attest to this innovation. Benjamin Girard, in 1889, highlighted his characteristic white light (fixed 30 seconds, then eight bursts) and his role as a geographical landmark. Today, although its fog horn is deactivated, the lighthouse remains a symbol of the Breton maritime heritage, managed by the interregional direction of the North Atlantic-West Manche Sea.

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