During the Lion Walk excavations 1971-4, an 11th century ditch was excavated at Site N. This large defensive ditch was situated at the foot of the town wall. It was dug in the late 10th or c.11th centuries, probably between AD 1050 and 1075 by the pottery found at its base. The lowest 1.4m of the ditch fill consisted of sand, gravel, occupation debris, Roman tile, greensand, and fragments of septaria and was the result of the sides of the ditch crumbling and sliding to the bottom with rubbish deposited mainly from the south The ditch has only been encountered at Lion Walk and does not extend around the whole walled circuit. Possibly because the Roman wall along the southern stretch was in a worse condition than elsewhere on the circuit and required reinforcing.<1><2>

Part of a large feature, possibly the north edge of the medieval town ditch, was recorded 6.5m south of the Roman wall line at 11 Short Wyre Street. <3>