This walk starts near the "Graciano" café in the town of Pedreiras. From there we pass Quinta do Calhariz, in the direction of Serra do Risco, to enjoy the plains and all the beauty of this part of the Arrábida Natural Park. The route follows trails and some rural paths, with the chance to see the Atlantic Ocean on a walk in perfect communion with nature. We'll have a fantastic view of the Serra do Risco cliffs, the highest in continental Europe with a height of 381 metres. It's a breathtaking view of the magnificence of Mother Nature.

Arrábida Natural Park:

The Arrábida Natural Park owes its name to the main geomorphological unit of the whole area, the so-called Arrábida mountain range, made up of 3 axes:

• The 1st is made up of small elevations on the outskirts of Sesimbra, the Risco and Arrábida mountains and the hills between Outão and Setúbal;
• the 2nd is formed by the Sierras de S. Luís and dos Gaiteiros; and
• the 3rd formed by the Serra do Louro and Serra de São Francisco.

The orientation of the mountain range is ENE-OSO (alpine orientation) with a length of around 35 kilometres and an average width of 6 kilometres. The maximum altitude is 501 metres at the Formosinho anticline.

To the north of the mountain range there is a vast area of plain that is widest near the western boundary of the park and narrows progressively as you move eastwards. The coastline is quite rocky, cut out by small bays with white sandy beaches topped by cliffs.

The Arrábida mountain range, and the area of plain that surrounds it, has a great diversity of soils, due to the multivariate constitution of the rocky materials that make up the parent rock. The vast majority of the soils are of sedimentary origin, although there are some eruptive intrusions. All the modelling visible in Arrábida today depends not only on aspects linked to tectonics and erosion, but also on the geology of the area, which is largely made up of limestone and dolomitic or detrital rocks.

The coastline is quite rocky, cut out by small bays with white sandy beaches and usually topped by cliffs of considerable height.

As is characteristic of regions whose geology is predominantly made up of limestone, the hydrography has aspects specific to this type of constitution, such as the non-perenniality and smallness of the watercourses.

Arrábida's vegetation has a high natural value, with three floristic elements converging in the area:

• the Euro-Atlantic, cooler, wetter and darker on the northern slopes;
• the Mediterranean, which is warmer, drier and brighter on the south-facing slopes; and
• the Macaronesian on the markedly maritime cliffs.

Serra do Risco and Terras do Risco

Legend has it that it was in this Vale do Risco that King Afonso Henriques "risked" dividing his troops, thus creating a death trap for the Moorish troops based at Sesimbra Castle. On the other hand, the presence of the skyline of the highest cliff above the sea on the Portuguese mainland presents itself as a perfect "risk" on the horizon. What is the reason for this name? We may not have an answer on this tour of a mysterious, unexplored area with unique treasures and views, accessing balconies overlooking the sea and travelling along old paths used by smugglers, climbers and, for a long time, the training ground for Portuguese soldiers going off to war overseas.

- Terras do Risco - Quinta do Calhariz - Roça do Casal do Meio - Varandas do Risco - Marmitas de Gigante - 381 metre high cliff of Serra do Risco - Natural landscapes -