This trail climbs up and down ravines that almost always open up above sea level - the hanging valleys. In the distant past, each hanging valley was associated with the mouth of a stream, and was created by a rapid retreat of the coastline which was not accompanied by the water’s edge.
The action of fresh and salty waters on the coast creates a jagged coastline, called a karst landscape, with a remarkable diversity of geoforms that can be seen in Praia da Marinha: arches, coves and islets.
Praia de Benagil is associated with the mouth of a pluvial stream that carved a narrow gully in the cliff. This beach has sheltered a fishing community dedicated to traditional crafts; nowadays, vessels are mainly busy with visits to the marine caves.
At Praia do Carvalho, you can reach the beach through a tunnel excavated in the soft Miocene limestones, where you can see a profusion of sea shells aggregated in the rocky groundmass. Among the Mediterranean coastal scrubland there is the Mediterranean dwarf palm, the only European palm tree, and you can see the Sardinian warbler, a small bird typical of the region.
After the deep green of Mediterranean vegetation comes a lunar landscape of naked, bare rock. Old legends are told about this great boulder, the Leixão do Ladrão, such as that of the Moorish princess who mourns the death of her lover, her tears create the paths and tracery so typical of limestone.
Near the Alfanzina Lighthouse grows a grove of Aleppo pine, one of the few trees that managed to settle in this rocky and arid terrain. Here, the pine forests function as ecological islands for tits, rock-thrushes or little owls. Dense vegetation favours mammals such as the rabbit, the Egyptian mongoose, or the fox.