Located on a massif south of Vila Praia de Ancora, the Cau Fortress is a defensive structure consisting of four fortified corners and a group of guard rooms united together by a stone canopy and a perfect circular arch, facade with porches and cannons facing the sea, built between 1699 and 1702 During the reign of Pedro II with the aim of defending the Portuguese coast against pirate raids, it was designated a Public Interest Building in 1967.