The Raya or frontier between the kingdoms of Castile and Aragón was fortified with a system of castles and walled-cities that were useful during the several conflicts that took place in the late Middle Ages. The Serón de Nágima castle defended the communication road between the axis of the Jalón river valley, which flows into the Ebro, and Duero valley. Its uniqueness stems from the fact that it is one of the few fortifications in the area where rammed earth is the only building system used. In this paper, the castle building fundaments are exposed mainly focusing on the techniques and building processes developed from the interpretation of the legible constructive signs in its walls.
The late medieval strategy for delimitating and defending the frontier between Castile and Aragón was in its systematic fortification. Ancient castles and Muslim fortifications were repaired and new buildings for defense were erected. The aim of the author's Doctoral Thesis, which gathers from the present paper, is to know the construction techniques of a selection of these castles, so as to interpret the building activity of that historical moment and analyze the systematization of these construction techniques within the historical, geographical and architectural context.The research method consists of a fieldwork in which a series of castles are documented and surveyed; they are previously selected after analyzing the bibliographical works of the medieval Soria's castellology.
References:Prunn Castle is perched on an almost vertical Jurassic outcrop high above the Altmühl river valley south-west of Regensburg. Its impressive appearance from a distance is matched by the views from the castle of the surrounding Altmühltal countryside.
Lords of Prunn were first mentioned in 1037, and they will have certainly chosen the site because of its favourable position on several transportation routes. The castle itself dates from around 1200, a time when many castles were being built. The Danube region centring around Kelheim became very important in this period under the Bavarian duke Ludwig I. One of the oldest parts of the castle is the 31-metre keep.
In 1288, Duke Ludwig of Bavaria acquired the castle from the lords of Prunn-Laaber. In the first half of the 14th century the duke then invested the Fraunberg vom Haag family with the castle.