During virtually the whole of the Middle Ages, Extremadura was an eminently frontier land. This led to intense warfare and frequent border changes. Witnesses of that time are the numerous fortresses which stud the most strategic points of the Villuercas-Ibores-Jara Global Geopark of the UNESCO.

Until well into the 13th century when the Reconquest was completed the frontier between the Christian and Moorish kingdoms was subject to frequent changes; it was sometimes in the vicinity of Córdoba and Seville but on other occasions it was marked by the valley of the Tajo. This meant that on the most strategic sites such as mountains and lofty hills the defensive structures of citadels, fortresses, and castles were built. Although these constructions were destroyed and rebuilt throughout the Reconquest, even today many of them continue to stand erect on their vantage points to dominate the landscape and very often the toponymy.

When the kingdom of Castile conquered the Moslems in the 13th century the town of Trujillo also recovered its territories, which became crown property; these included Logrosán. One of the Moslem fortresses of this area was that established on the Cerro de San Cristóbal of this village. Remains can still be seen of the hisn (castle) and an Arab settlement surrounding it.

Another of the Moslem fortifications of the Geopark is that of Cañamero, which is located on a quartzite crag with some remains from the Chalcolithjic period. Ruins of the castle can be seen together with some fragments of the walls. Likewise the cistern and a central tower can still be made out. By 1220 the fortress was already abandoned and in the 15th century the order was given to demolish it as it served as a refuge for the villains who attacked the pilgrims of Guadalupe. Close by is the so-called Cueva de la Mora (Cave of the Moorish Girl) which evokes the Arab past of these crags.

In Solana de Cabañas near the Cancho del Reloj there are remains of another of these fortifications. On the highest point of the so-called Sierra del Castillejo, which is a clear reference to the former construction, stand the solidly built remains of one of them and an extensive settlement. Written sources of Alía also mention the existence of one. 16th-century documents say of this castle «questá a quarto de legua de Halía fue morada antigua de moros y ou dia pareçen edifiçios deçimientos y casares asiento de pueblo y planta de árboles…» During the questioning of the Historical Appellate Court of 1792 a negative answer was given as to whether castles existed in Alía. Its remains can be found on the Monte de Santa Catalina which overlooks the village. On this site, which dominates a large part of the valley of the Jaligüela, there are numerous scattered remains of both constructions and pottery and cave paintings.

The Castle of Espejel stands in Valdelacasa de Tajo. There are records of its existence going back to the 12th century, in which Alfonso VIII gave it to the Order of Santiago, dating its construction as being from the 10th century. It is a very characteristic example of this type of fortress with its quadrangular central bastion and towers on the corners. The remains of the barbican and the wall to protect the water supply can still be seen. It was built of granite, mortar, and slate. The old name of ‘espechel’ refers to its watchtower function.

Also near the Tajo is to be found the Castle of Alija, which is erected on the granite blocks watching over the point where the Gualija flows into the Tajo. It has a privileged strategic location as it controlled passage on the old road which over the bridges of El Búho and El Conde reached the plains of the Campo Arañuelo. On the other side of the valley was the watchtower of Peñaflor, of which only traces of the foundations remain. Other fortresses of Moslem origin which can be seen in the Geopark are the Castle of Cabañas and the Fuerte de Castros in Villar del Pedroso. Owing to their importance each of them deserves a chapter of its own.