Built in 1616 by the Portuguese to protect a city that had just been founded, the fortification is located on Ponta Maúri, at the confluence of Guaianá River and the Bay of Guajará, marking the entrance to the port and the navigation channel that runs alongside Onças Island in Belém.

In 1590 in Recife, the Portuguese built a fort on the reefs with the purpose of defending the port’s access bar, and called it Castelo do Mar [Castle of the Sea] or Fort Laje do Picão.

The battle of 17August 1645, which became known as the Batalha de Casa Forte(Battle of ‘Strong House’), in allusion to the place where it was fought, was one of the most notable victories for Pernambuco in the war against the Dutch.