Berlenga Lighthouse

The Berlenga Lighthouse, officially known as the Duque de Bragança Lighthouse, is a historic structure located at the summit of Berlenga Grande Island in the Atlantic Ocean, Portugal. The island, a granite mass anchored several miles off the coast northwest of Peniche, hosts the lighthouse at its highest point, at coordinates 39º 24',99 N latitude and 09º 30',47 W longitude. The lighthouse is managed by the Portuguese Navy’s Directorate of Lighthouses (Direção de Faróis) and continues to function as an active coastal lighthouse today.

The construction of the lighthouse was first ordered by the Pombaline decree dated 1 February 1758, establishing its historical origins in the 18th century. However, after a prolonged delay following the initial decree, the actual construction process gained momentum with the Ministry of Finance decree dated 12 December 1836. Under the supervision of engineer Gaudêncio Fontana, the tower was completed in 1841 and officially commissioned in 1842. The structure was built to serve as a navigational reference point for ships approaching ports such as Lisbon and Porto and to ensure safety in the hazardous waters of the Atlantic. The attached dwellings were completed in the years following the tower’s construction, between 1851 and 1860.

^{Berlenga Lighthouse (}Flickr⁾

The Berlenga Lighthouse is a rectangular prismatic tower constructed of masonry and cut-stone cornerstones, featuring a balcony at its summit. This white-walled tower, with a red lantern housing and balconies, stands 29 metres tall, with its light source positioned at an elevation of 121 metres above sea level at sea.

Since its commissioning, the lighthouse has undergone several technological transformations:

• Initial System (1842): The original lighting system consisted of a catoptric apparatus with sixteen Argand lamps fueled by oil and equipped with parabolic reflectors. This system, driven by a clockwork mechanism, produced white light with a flash every three minutes and a brief flash every ten seconds.

• Hyper-Radiant Optics (1897): One of the lighthouse’s key optical upgrades was the installation on 6 November 1897 of a Fresnel hyper-radiant optical apparatus. Powered by incandescent vapor, this device produced a group of three flashes every 30 seconds, becoming one of only two such optics installed on Portuguese lighthouses of this type.

• Electrification and Range Extension (1926): In 1926, the lighthouse was electrified using generator motors. This modernization increased the light intensity to approximately 27 million candelas and extended the light’s range to 36 nautical miles.

• Automation and Transition to Solar Power (1985–2000): The lighthouse was automated in 1985, eliminating the need for resident keepers; the old hyper-radiant optic was removed and replaced with a PRB 21 system. The most significant environmental transformation occurred in 2000, when both the lighthouse and dwellings began operating entirely on solar power. During this transition, a modern rotating beacon, the TRB-400, was installed. In 2009, the TRB-400 was replaced by two LED optics. The current light characteristic is Fl W 10s (White Flash every 10 seconds), with an estimated range of 20 nautical miles.

^{Architecture of the Berlenga Lighthouse (}Flickr⁾

The lighthouse has been operated fully automatically since 1985. There are no permanent lighthouse keepers stationed at the tower. Monitoring and maintenance are carried out from the mainland by the Portuguese Navy’s Directorate of Lighthouses.

The lighthouse is directly protected and managed by the Portuguese Maritime Authority (Autoridade Marítima Nacional) and the Navy’s Directorate of Lighthouses. Its historical significance, combined with the island’s status as a Biosphere Reserve, ensures its protection as both a cultural and environmental heritage site.

Although the lighthouse is a symbol of the island and a tourist attraction, it is currently closed indefinitely to visitors due to operational issues. Visitors may observe the lighthouse from a distance and utilize the surrounding diving sites within this UNESCO-protected natural area.