In dominant position over the village and the mouth of the Arade river, its elevation separates two beaches: the Praia da Angrinha and Praia Grande. Worked with the Fort of Santa Catarina, which was opposite him in Portimão, in the defense of the river estuary.
The primitive fortification of the place dates back to a watchtower built under the reign of King John II (1481-1495). Later, when the Ferragudo village was founded (1520), it is believed to have been surrounded by a defensive wall erected on the remains of another, older, probably dating from the time of the watchtower construction.
According to the report Alexandre Massai, the wall still existed in 1621, as they state “a fenced place called Ferragudo” (Description of the Kingdom of Algarve …, 1621).
Aiming at the defense of that estuary, before the village, downstream, on a rocky elevation, one artillery bulwark was erected around 1643.
The force of the elements (tides and storms), culminating in a violent storm in 1669, caused severe damage to the bulwark.
Repaired in 1754, an inspection made by the Kingdom of Algarve Governor, D. Rodrigo de Noronha and Antonio Meneses, the fort was considered in perfect condition. Then had two artillery batteries:
the Low Battery, with three artillery pieces;
the High Battery, artillery by four.
The following year was severely damaged by the earthquake of 1755, including the foundations. In 1765 a new report realized that all their quarters were in ruins, having spent $ 80 000 réis in its rebuilding.