In October 1977 a trench was opened between the Castle Keep and the Bailey Chapel. The trench was c.2m wide and was located immediately to the east of the barbican wall. The investigation was intended to clarify the stratigraphy in the area and in the hope of obtaining a stratigraphic link between the keep and the chapel. The latter aim was defeated by the presence of massive post-medieval disturbance, all levels having been truncated by the 1933-4 clearance of the chapel foundations. Excavation below these levels was limited to a pit and hole which had exposed the surviving section of the facing wall. A shaft was also sunk into a massive robber pit. <1>