The Castle of Terena, Alentejo, located in the village and parish of the same name, municipality of Alandroal, Évora District, Portugal.

Dominant on top of a hill, he joined the Guadiana river line of defense along with the castles of Juromenha, Alandroal, Monsaraz and Mourão.

The oldest documented information on the village date back to the reign of King Afonso III (1248-1279), when the royal knight-Gil Martins and his wife, Maria João, became a charter in 1262. Although it is not known a date need for the start of the castle construction, is believed to have taken place in this period, since the border of the Upper Guadiana qualified as strategic importance to the Portuguese crown, and given the interest shown by King Dinis (1279-1325) in the consolidation of this linde, still ensured by the castles of Elvas, Juromenha and Alandroal.