The fort, which is in a dominant position on a rocky escarpment, is star-shaped, with four triangular bastions and five platforms for the artillery. Following a Late Renaissance architectural style, it is protected by a moat to the east, with access by a bridge. The main portal contained a crowned national coat of arms and a plaque recording the fort’s establishment. It was built to reinforce the defense of the south of Peniche, crossing fire with the Fortress of Peniche. Its construction was part of a strategy for the entire coastline of Portugal that aimed at enhancing the defence offered by a limited number of fortresses with the addition of a succession of small forts. Construction began in 1641 and was finished in 1645. Further expansion was carried out in 1665. The fort was seriously damaged by the earthquake in 1755 that affected most parts of Portugal, with part of the battery facing the sea being destroyed. In 1796 five gun emplacements were added and in 1800 a new battery with 15 cannon was erected to the east of the fort to both cover the beach and cut off access from the land. Restoration work was also carried out in 1832 during the Portuguese Civil War.