This castle, of Roman origin, was built under Arab domain. After the Christian conquest (1148), the castle was repaired and enlarged many times. During the reign of King Manuel I, the governor orders the construction of a palace and changes some parts of the castle. In the Alcaide’s palace, manueline windows can be found. The chimney in the main room and the portal with the royal coat of arms of the Noronha family is also from this time. The palace suffered great damage with the 1755 earthquake. During the 20th century it was found completely in ruins. It was restored in order to house the State Inn (Pousada) – the first state inn in a historic building.