Between his stones still the primitvas identify medieval towers, integrated to the modern fortification. Surrounded with deep pits, the fort thinks on a small hill that it dominates the lands of Badajoz and Olivenza, to approximately 250 meters altitude. It is composed by five bastions joined by curtains and defended by an alone door, which was possessing a drawbridge. In his interior between other ruins, those of the Church remain where there were celebrated the royal weddings of Alfonso IV of Portugal by Beatriz of Castile, and the daughter of these, Maria of Portugal by the Castilian Alfonso XI. The enclosure had great protagonism in the fights between both peninsular nations, being taken by Spain in several occasions. This strength turned out to be very affected by an explosion of his polvorín and for the earthquake that destroyed great part of the city of Lisbon.