Castelo de Santiago do Cacém.
The primitive human occupation of this site dates back to Celtic tribes. At the time of the Romanization of the Iberian Peninsula, the then existing village was called Miróbriga, forming part of the conventual jurisdiction of Pax Júlia (currently Beja).
Occupied by the Alans during the first decades of the 5th century, it was abandoned in the 6th century, with the population moving to the neighboring hill, closer to the sea. The new settlement was successively dominated by the Visigoths and, at the beginning of the second decade of the 8th century, by the Muslims, when it came to be known as Kassen.