Aspur castle is a type ofmedieval fortification that is sited on aspur of a hill or mountain for defensive purposes. Ideally, it would be protected on three sides by steep hillsides; the only vulnerable side being that where the spur joins the hill from which it projects. By contrast, aridge castle is only protected by steep terrain on two sides.
A spur castle was one of several types ofhill castle. Depending on the local topography, a spur castle may have relied mainly on its inaccessible position or may have integrated further features such asshield walls and towers into the defences. In addition castle builders may have improved the natural defences of the terrain by hewing into them to make the hillsides harder to climb and reduce the risk of landslide. A classic feature is theneck ditch, cutting off the spur from the rest of the hill. A long spur castle is sometimes, but not always, subdivided into a lowerward and a more strongly defended upper ward (or even a succession of three or more wards).
High spur andhilltop castles were built and improved by theFranks to hinder increasing use of the counterweighttrebuchet. In the case of spur castles, heavy siege machinery could only be deployed on the uphill side enabling defensive works and forces to be concentrated there.[1]
The Krak des Chevaliers from the southwestRudelsburg in the Saale valley, Germany
The crusader castleKrak des Chevaliers in Syria lies on a spur accessible from the south. At the same time, it has strongconcentric castle defences on all sides.[2]
TheCitadel of Salah Ed-Din, western Syria, has defences concentrated on the vulnerable side of the spur, most notably a deep ditch. The lower bailey at Saône (as the French call it) has weaker walls and towers.[3]
TheAlamut Castle inPersia (now northwestern Iran), was atop a narrow rock base rising approximately 180 m. It was thought to be impregnable to direct attack.
TheAlcázar of Segovia, centralSpain, is on a narrow spur with deep drops all around except from the east where it is approached on level ground.
Stirling Castle,Scotland, is on a narrow spur with drops on three sides and a gentle slope providing access from the south-east.
Château de Chinon, centralFrance, was used by the counts of Anjou in the 12th century. In 1205, it was captured by the French king and was the largest castle in theLoire valley.
