Costa Sul links Vila do Porto with Praia Formosa through a corridor where built heritage, geology and the Atlantic meet. Leaving near Forte de São Brás and Ribeira de São Francisco, the walk reaches Pedreira do Campo, an area noted for marine fossils and pillow lavas that preserve evidence of a submerged phase in Santa Maria’s formation. Farther on, Gruta do Figueiral recalls the former extraction of limestone and clay, activities that left visible marks on the landscape.
Beyond Touril, the setting becomes more rural and wooded before the descent to Prainha. The trail then follows an exposed coast, passes the ruins of Forte de São João Baptista and ends at the broad bay of Praia Formosa. Dark rock, green slopes and pale sand give this linear crossing a distinctive character. Over a comparatively compact distance, walkers can observe geological features that are unusual within the archipelago together with coastal defences connected to the history of Vila do Porto.
The progression ends in the same broad coastal sector as Prainha, yet each stop reveals a different use of the shore: extraction, defence, movement on foot and recreation. This continuity helps walkers understand the southern coast beyond its immediate scenic appeal and places the geological features within a lived landscape.