The 16th-century star fort sits on a hill above the western edge of town and has the best view of the city, the Sado estuary, and the Tróia peninsula on the far shore. The interior chapel is tiled floor to ceiling with blue and white azulejos depicting the life of São Filipe.
The fort was for many years operated as a state-run pousada (historic hotel), and although that operation has wound down the grounds and chapel remain open to visitors. Walking up takes about 20 minutes from the centre; the views alone justify the climb.