Geographic Setting

Arrábida Natural Park is located on the South part of Setúbal peninsula (see map of protected areas). It encloses a somehow limited geographical area but comprises a great diversity, unique in Portugal, of habitats and, correspondingly, of plant and animal species.

The great interest in the orchids of Arrábida lies precisely in the fact that, in this small geographical area and following the diversity of habitats, about half of all Portuguese species are concentrated.

Geologic Setting

The morphology of Arrábida Natural Park and surrounding area is marked by the mountains of Arrábida mountain range, the valleys that interweave them and vast plains following to the North and the West. The mountain range consists essentially of limestone rocks, often visible in whitish outcrops. Following an ENE-WSW orientation, it is formed of three main mountain chains with the same orientation, that, from North to South, increase in altitude and degree of inclination of their slopes.

To the North we have the ridge formed by Serra de São Francisco and Serra do Louro. It is separated from Serra do Gaiteiro and Serra de São Luís, the second mountain chain, by Vale(valley) dos Barris and Vale de Alcube. At the Southeast end of these mountains, Vale de Picheleiros separates them from the greatest mountain chain, extending along the seashore and running West, formed by Serra do Risco and Serra da Arrábida. To the North, also extending to the West there's a vast plain consisting mainly of siliceous sands.

The sands, clays and "brechas" (clastic rock of sedimentary nature made of rocks of different types and colours glued together by a mass of finer and reddish cementation) were caused by movements of emersion long after the formation of the limestone core of Arrábida.

Part of Arrábida Natural Park, although territorially separate, there is the Special Protection Zone (ZEC) Arrábida-Espichel that comprehends all the coastal area from Sesimbra to Praia(beach) da Foz passing by Cape Espichel. This site consists mainly of limestone rock outcrops and sandstone.