The fort is located to the south of Monte do Castelo, in Serra do Cabeço, where there was originally a hermitage under the invocation of Saint Sebastian, demolished during the fortification works.

[2] Its importance stems from it being the best preserved example of the extensive process of renovation of the town's defensive system in the mid-17th century.

[1] Work on the fort began in April 1641 under the reign of John IV (1640-1656), from 1641 onwards, during the War of Restoration of Portuguese Independence, with the aim of strengthening the defense of this strategic section of the border.

[1] Its design aimed to modernize the protection provided by the old medieval castle, transforming the village into the main stronghold of the Algarve at the time.

[2] The main gate faces north, towards the village, communicating with the old castle through a wall and covered entrance.