Planetrees

The eastern part of the surviving section (approximately 20 m in length) is built as Broad Wall, 10 Roman Feet wide. The eastern section (approximately 15 m in length is built as Narrow Wall, 8 Roman Feet wide, yet still on foundations clearly installed for a Broad Wall. The join is archeologically interesting, as it suggests a change in plan during construction. Also present on the narrow wall stretch is a culvert. The stones forming the culvert cross the whole width of the foundation (built for the broad wall), suggesting that the culverts were constructed at the same time as the foundations, rather than along with the curtain wall.