Designated in 1981 (Partial Nature Reserve), 1998 (Nature Reserve)

Offshore and well into the ocean realm 9 km to the NW of Cape Carvoeiro, close to the fishing town of Peniche, this Nature Reserve includes all the island groups that make up the Berlengas archipelago: Berlenga Island itself with a number of smaller reefs around, the Estelas cluster lying just over a kilometre out to the NW, and the steep Farilhões almost vanishing in the distance, a further 5 km away to the NNW together with a group of small low-lying reefs called the Forcadas.
The Berlengas Nature Reserve covers a surface of 9560 ha overall, but only 104 ha are land, almost 99% being sea around the islands. Berlenga Island is the only one within this group to support human habitation, but nowadays there are no permanent residents and occupation levels fluctuate widely according to the season and weather conditions.
Despite a strong Mediterranean influence, most obvious on the south-facing slopes which provide some shelter from the salt-laden ocean winds, Atlantic conditions prevail within the archipelago. The vegetation is mostly low and sparse, limited to a succession of rock-encrusting lichens and small vascular plants, including grasses and a few occasional shrubs of drought-resistant species able to survive and thrive under constant salt spray and other severe environmental constraints. Several interesting plants can be found here, including endemics like Armeria berlengensis, Herniaria berlengiana and Pulicaria microcephala.
Among the vertebrates there are only two reptile species living in the archipelago, the ocellated lizard Lacerta lepida (now almost disappeared, and with a distribution in historical times that has been restricted to Berlenga Island), and the much smaller wall lizard Podarcis carbonelli berlengensis, which is quite common and may still be found across the archipelago. Compared to their closest relatives on the mainland, both of these island reptile populations have developed a number of peculiarities in body shape and behaviour.
Seabirds are the dominant vertebrates ashore, and many thousand breed in this area. The species diversity is considerable and results from contrasting climatic influences. This diversity is enhanced by the occurrence of a few species living virtually on the edge of their geographical distribution. The archipelago still extends the southern limit of the breeding area of the common guillemot Uria aalge, but only a few metres away is the northernmost breeding limit for Cory’s shearwater Calonectris diomedea, to name just two such cases. The yellow-legged gull Larus michahellis has its largest Portuguese colony on Berlenga Island, with well in excess of 20 000 birds still breeding there despite regular population management that has been carried out for almost two decades.
Humans have visited Berlenga since ancient times, and in the classical era Mediterranean sailors knew these islands from their voyages of trade and discovery. The Romans included Berlenga as part of their empire some twenty centuries ago. Much closer to our times, monks of the Order of St. Jerome settled there in the early 16th century, but only for a few decades before they had to withdraw due to the harsh living conditions and constant harassment by raiding pirates.
Privateers and pirates (from Europe and also from the North African coast) were a common sight around Berlenga for many years. Their presence was a major nuisance to trade and fisheries, extending well into the 17th century. To curb their attacks, the fortification of S. João Baptista was then erected on rocks in a sheltered bay on the southern shore of Berlenga, to help defend a strategic position there. It is now acclaimed as a major attraction for many summer visitors on Berlenga, rivalling the lighthouse that was built in 1840 on the plateau topping the island, to help make navigation safer in the 19th century.
Rulers of their time, monks blessed by their faith, the mighty military men and all the dignitaries that were sent in by the authorities, always had a precarious foothold on Berlenga. In sharp contrast, the unobtrusive fishermen did well in these waters and have been around for centuries, since the dawn of recorded history. They are still there now and are still going strong.