The tower was originally built in 1519 in the middle of the Tagus to defend the mouth of the river and the Hieronymite monastery. The earthquake altered the course of the river, and this five-storey Manueline tower now stands next to a beach. The Romanesque-Gothic structure is adorned with Venetian-style loggias and small domes reminiscent of Morocco. Jutting out from the tower, facing the sea is a platform. On the ground floor, the openings through which prisoners were thrown into pits can be seen.
