San Isidro lighthouse, Historical maritime lighthouse in Magallanes Province, Chile

San Isidro lighthouse is a modest structure standing about 8 meters tall on the Brunswick Peninsula and serves as a navigation aid for ships in the Strait of Magellan. Its white flashing light pattern warns captains of the treacherous coastal waters along this southern route.

The lighthouse was built in 1904 following a study by George Slight, then inspector general of lighthouses, and executed by the Chilean contractor Luis Camuzi. The site was chosen as the only accessible spot for a light serving the turn of the Strait of Magellan where its waters meet the coast at Punta Arenas. It stands 10 miles south of the Spanish settlements of Nombre de Jesús and Rey Don Felipe, whose colonists died of hunger and cold.

The name recalls Isidore the Farmer, a Madrid-born saint canonised in 1622, though the sources give no reason for the dedication. What visitors notice today is the setting: the light stands against the Cordillera Darwin beside dense native forest, and from the cape the Strait of Magellan opens toward the Cruz de Froward, Fort Bulnes and the fishing hamlet of San Juan.

The lighthouse can be reached by land from Punta Arenas, about 90 km south, along a paved road that ends in gravel and follows the shore of the Strait of Magellan. Excursion boats also run to it by sea. The site sits at the tip of the Brunswick Peninsula, with the Darwin Range behind it.

The lighthouse stands about 10 miles south of Puerto del Hambre, where in the 16th century Spanish settlers founded Nombre de Jesús and Rey Don Felipe; the colonists died of hunger and cold. The site was chosen because it was the only accessible spot for a light at Cabo Froward, where the Strait of Magellan bends and its waters strike the coast off Punta Arenas.