For almost a millennium there has been a Moslem fortress above the village of Cabañas del Castillo on one of the impressive vertical walls of the western area of Las Villuercas. In former times from this watchtower it was possible to control the routes and roads which ran between the Sierra de Ortijuela and the valley of the River Berzocana to the southwest and the valley of the Almonte to the northeast. The remains of the fortress which shrouded in legend stand balanced on the crags are still spectacular.

The origin of this fortification goes back to about the 12th century, although everything points to the fact that it was built on an earlier Moslem building. When the Christian kingdoms reconquered the territories of Trujillo in the XIV century, the Castle of Cabañas became part of the Feudal Estate of Oropesa and the Marquisate of Jarandilla. García Álvarez de Toledo, who took it for King Henry II, then undertook its restoration. In time the castle passed into the hands of the Duchy of Frías, owing to which it took the name of Castle of Frías. The location of this fortress is a particularly privileged one on a crag of difficult access over 70 metres high and dominating two valleys. The natural relief of the terrain meant an added defence to the walls of the castle itself. This was important during the period when Extremadura and precisely the area of the current Villuercas-Ibores-Jara Global Geopark of the UNESCO was considered to be clearly frontier land. This bastion was part of the complex Moslem defensive system intended to defend the Andalusian territories south of the Tajo, the area known as Marca Media or Al-Tagr Al-Awsat in the times of the Omeya de Córdoba emirate.

The Castle of Cabañas was built of local materials, quartzite, and mortar. In the openings of doorways and windows brick was used. Some of these windows still survive in which can be appreciated the beautiful shapes of small horseshoe arches, one of the few concessions to ornamentation in a construction intended purely for defence. The part of the construction which is nowadays best preserved is that which may have been the keep which rises above the remainder of the ruins. The ruins of another smaller tower have also been preserved, like the previous one in the shape of a prism, together with the design of several of the sections of the walls. The remainder of the ground plan of the castle spreads out as if balancing on the upper part of the narrow quartzite crest, owing to which it has an irregular, narrow, and elongated shape. The entrance is protected by a bastion with a wall on the edge of the cliff. Then we come to the main entrance, which is also fortified.

On the lower part of the crag of the fortress lies the village of Cabañas del Castillo, the history and name of which are firmly linked to those of the castle. A curious legend explains the origin of the fortress. According to tradition, in these sierras lived a lizard so large that with a flick of its tail it was capable of causing landslides and moving large rocks. The reptile controlled seven leagues and terrorised the people of those valleys, who did not dare to roam abroad. One day a thief who had been stealing from the church of the nearby village of Jaraicejo took refuge among the rocks of the sierra to escape from the law. When the lizard tried to attack him the man dazzled it with a gold patera and killed it with a dagger. Suddenly the bandit became a hero and was allowed to build a castle on the spot where he had killed the monster.