Sto. António Ravelin hill was requalified in the XXI century, which included the rehabilitation of the military structure of the Ravelin, the Chapel/hermitage of Sto. António, the Mill and Sto. António Square, as well as the building of a Territory Interpretation Centre, with coffee shop, an outdoor amphitheatre, an Andalusian-inspired garden and space for traditional kitchen gardens. The Territory Interpretation Centre acts as a reception area, a place with information and starting point for cultural itineraries and visits to the county of Castro Marim, being also an excellent natural viewpoint, with 360 ° visibility. In addition, it has a virtual viewpoint of the entire county that, besides informing, also encourages visits to the various types of heritage: historical; natural; and knowledge.

Sto. António Ravelin is a small fort, built in the reign of King João IV, to control the Guadiana estuary. With vital strategic importance, it is located uphill on Rocha do Zambujal, on the east side of the village, and was connected both to the old castle and to the core of São Sebastião. Inside the Ravelin was built the Chapel of Sto. António, a baroque building of solid architectural quality, with a square chancel bounded by strong corner-pillars.