Ground penetrating radar survey and test pit evaluation by R Poulton of SCAU carried out in advance of remedial works to the 12th century keep. The results of the survey suggested that fragmented wall foundations might lie beneath the top of the motte, and that the keep had been constructed by cutting away the motte. This effectively created a foundation trench at a distance of 2--4m from the keep walls. The test pits confirmed the latter, but did not impact on areas where the foundations were suggested to lie. The excavation work also showed that the medieval ground level was similar to that at present, and that undisturbed medieval layers lie just below the tarmac surface on the top of the motte.