São Francisco Xavier Fort is its original name, but it is known among the Porto residents as Castelo do Queijo, since it was built on top of a granite rock which has a rounded shape resembling a ball-shaped cheese.
This designation came about in the 17th century, when the fort was built to defend the coast from pirate attacks coming from Northern Africa. The idea of erecting the Fort of San Francisco Xavier is most likely to have arisen in the sixteenth century, but since there was not much strategic interest at that time in that area, construction was postponed.
Despite possessing all the features of a military building, tailor made for the defence of the coast – walls, a moat, as well as watchtowers resting on triangular corbels – the truth is that it never truly served for the purpose it was intended. During the Civil War (1828-34) it was occupied by the troops of D. Miguel and as a result part of its structure was destroyed. It was abandoned and plundered for some time, however, after being restored, it is open to the public today, having a small museum and housing exhibitions and other events.