Set on a hill, between 275 and 325 m high, it occupies a prominent position in the surrounding landscape, providing ample views over the plain to the west and over the Guadiana valley and the Spanish raia to the east.
Considered one of the oldest villages in Portugal, Monsaraz registers signs of settlement since prehistoric times, being initially a fortified hillfort.
During the reign of King Alfonso III of Portugal, when the monarch granted him the first charter fixing the limits of the county, the primitive core of the castle was built, including the keep, the matrix and the Gothic court, which interior houses the fresco of "The Good and the Bad Judge".
Throughout the 16th century and with the Manueline reform of the charter, the town grew and a Brotherhood of Mercy was established locally.
During the Restoration Wars, due to Monsaraz's proximity to the Guadiana and the Spanish border, the Crown had a new fort built around the town, using the Franco-Dutch system designed by Sébastien Vauban. The project, designed by French engineers Nicolau de Langres and Jean Gillot, provided for the construction of a new wall consisting of the Fort of São Bento, the "defensive key of the Arrabalde", with a rampart and artificial curtain, the Fort itself, in the shape of a star, the Bastion of São João and the Bastion of the Castle.
When the county seat was transferred to Reguengos de Monsaraz in the 19th century, the fortification was abandoned and some of its buildings collapsed, but the walled structure is still a striking feature of the town of Monsaraz.
