The fortress of Santiago da Barra is located near the sea, and the first fortification is believed to have been placed there along the mouth of the Lima River, dating back to the reign of King Afonso III in the thirteenth century, however, the earliest confirmed date is in the fifteenth century, when A fort was built there during the reign of King Manuel I, and this is indicated by various Manueline architectural features, notably the "Roqueta Tower" in the southwestern stronghold of the present fort.