A substantial ditch (F4), c.3.5m wide, extended roughly from N to S across the centre of the site.<1>
The ditch had a greyish-brown loamy fill, with some orange sandy mottles. The bottom of the ditch was not reached during machine-trenching, so its depth remained unclear. It was not possible to hand dig a section across F4 due to safety concerns. A post-medieval potsherd and a ?peg-tile fragment were recovered during machining, and probably came from the backfill of F4. It seems likely that F4 was a post-medieval field boundary ditch, although a ditch in this position has not been identified on early maps. Another possibility is that F4 was part of a Parliamentary earthwork, dating to the Siege of Colchester in 1648.