The Fortress of Saint James of Sesimbra, also known as the Fortress of Santiago, is a cool old fort located in Sesimbra, Portugal. Built between 1642 and 1648 to beef up Portugal's defenses against Spanish attacks, this fortress has a solid structure with a star-shaped plan and a touch of Renaissance style. It used to house the Military Government and even served as a summer pad for the king's illegitimate kids back in the day. In 2016, the Fortress of Santiago welcomed that which is the great project for the space: the Sesimbra Maritime Museum, which provides information about the history of the sea,  fishing and the fishing community since the earliest times to the present.

The Fortress also houses the Tourist Office, the store Yes Sesimbra and a cafeteria with a terrace overlooking the sea, and whose speciality is the Arrábida's craft beer!