The castle's location on a rocky outcrop affected the layout; it was not possible to have one unified structure, and like many castles, Loarre was a collection of buildings bounded by curtain walls. Originally the internal plan included two towers and a chapel behind several curtain walls. Towards the end of the 11th century, an additional chapel was built in Romanesque style just outside the castle walls. The outermost walls of the castle and their eight towers were erected in the 13th or 14th century. The church and castle have been the subject of numerous restorations, a major one in 1913 and subsequent ones, particularly during the 1970s, have resulted in the rebuilding of many walls and towers that had fallen into disrepair. At least three towers, two of which survive, the keep (Torre del Homenaje) and the "Tower of the Queen" (Torre de la Reina), as well as a chapel dedicated to Saint Mary of Valverde and connecting walls are attributed to this campaign. The keep was built in an isolated position in front of the fortifications, to which it was connected by a wooden bridge. It contained a basement and five floors. The Torre de la Reina, comprising a basement and three floors, is particularly noteworthy for three sets of twin-arched windows, with columns of exaggerated entasis and trapezoidal capitals that have been related to both Lombard and Mozarabic architectural forms. The chapel is composed of a single-cell nave with an eastern apse covered by a semicircular vault. The original timber roof of the nave was replaced by a vault at the end of the 11th century.