The monument includes the buried and upstanding remains of the southern section of a late Iron Age or Romano-British linear boundary earthwork, located some 3km south of Colchester town centre and known as the Berechurch Dyke. The section of the dyke extends over a distance of about 1.7km, following a narrow zigzag course (first SSW, then SSE, then s) between Berechurch Hall Road and the Roman River. From Berechurch Hall Road to Park Farm (a distance of about 1.3km) the bank, or rampart, is surmounted by a modern road surface and the ditch remains as a marked depression along most of the eastern side. An excavation across the roadway in 1984 demonstrated that the original bank survives to a height of 1m below the road and measures up to 13.5m in width. The depth of the largely infilled ditch was not established, although its width was recorded as 5.5m. The dyke continues southwards beyond the road and survives as a pronounced earthwork running through Charlotte’s Grove towards the north bank of the Roman River. Here the bank stands some 2m high and 9.5m across and the ditch measures 4m wide and 2m deep. Excavations immediately to the west of the dyke in 1929 and in 1996 revealed a number of slight ditches which have been interpreted as enclosures. These enclosure ditches (not included in the scheduling) contained pottery dating from the late Iron Age. They appear to have been deliberately sited alongside the bank and this relationship provides some indication of the date of the dyke’s construction. The dyke’s continuation to the north of Berechurch Hall Road has been established through excavation, although the route is mainly overlain by modern developments and is not included in the scheduling. At Monkwick Cemetery, 1.4km to the north, the dyke was broken by an entranceway before turning east and continuing (as Barnhall Dyke) for at least a further 800m. This change in direction may have been designed to avoid an extensive late Iron Age burial ground to the south of the modern town centre, and Berechurch (and Barnhall) Dyke, the only earthwork boundary on the eastern side of the territorial oppidum, may have been built to provide defence against attack from the direction of the Colne estuary. Furthermore, since the Roman Empire presented the only sea-borne threat to the oppidum, it has been suggested that the dyke was constructed as a specific response to the invasion planned (but not carried out) at the time of the Emperor Caligula (AD 37-41). Other authors maintain that the linearity of the dyke implies construction in the Roman period (after the successful invasion of AD 43) and suggest that its function was political rather than defensive The modern road surface, together with all fences and fence posts, are excluded from the scheduling, although the ground beneath these features is included. <1>