Spur castle

Depending on the local topography, a spur castle may have relied mainly on its inaccessible position or may have integrated further features such as shield 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 the neck ditch, cutting off the spur from the rest of the hill.

High spur and hilltop castles were built and improved by the Franks to hinder increasing use of the counterweight trebuchet.

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.