Designated in 1971 (Nature Reserve), 1976 (Nature Park)

Located south of Lisbon, between the cities of Setúbal, Palmela and Sesimbra, with an area of 17 300 ha, the Park has a heterogeneous geography with valleys surrounded by limestone mountain ridges and the Arrábida mountain overlooking most of the area. The highest point is Alto do Formosinho (499 m). This Nature Park has some of the most significant examples in Portugal of Mediterranean maquis, which here maintains similar features to the original, with a large number of microhabitats. Plants such as the myrtle Myrtus communis, mastic tree Pistacia lentiscus, strawberry tree Arbutus unedo, wild olive Olea europaea var. sylvestris and kermes oak Quercus coccifera can reach tree size in some places. In some of the woods, the Portuguese oak Quercus faginea has become the dominant species. The brushwood that covers most of the Arrábida mountain has great botanical value and a wide variety of aromatic plants are found there, such as rosemary Rosmarinus officinalis, lavender Lavandula spp. and Thymus spp.

The human presence in the area, going back to the Palaeolithic with remains from the Copper Age and significant evidence of the Roman presence, has left many traces in the cultural landscape. The Arabian presence is also commemorated by the castles of Palmela and Sesimbra (12th century).
The region has preserved important elements of its architectural heritage, with some good examples in various manor houses and other dwellings, including a varied group of Renaissance, Mannerist and baroque architecture in the Azeitão area, from the early 16th century.
There is a long tradition of producing glazed tiles, as well as the famous Azeitão cheese and internationally renowned table wine and Muscatel.
The importance of Arrábida in terms of nature conservation includes the neighbouring coastal region, considered a marine biodiversity hotspot, with more than 1000 species of marine fauna and flora. The preservation of this underwater legacy is the main objective of the Professor Luiz Saldanha Marine Park, created in 1998. The Oceanographic Museum, located in Santa Maria fort (17th century) in Portinho da Arrábida, displays some of the native species and also functions as an information centre.