NHER 21806 (Monument record) - The Green Dyke (Late Saxon/medieval)

Mentioned in a document of 1379 as running from Hardwick Causeway (the present A47) to Jerry's Dam (now marked as Clarke's Chase by Ordnance Survey). Forms parish boundary in places. On Hardwick Narrows, survives up to 6.1m (20ft) high in places. Suggested as original east bank of reclaimed area by informant [1].
E. Rose (NAU) 16 October 1985.

The tall section mentioned must be that at TF 631 178. This was not examined at close quarters; it has a footpath to the east and a ditch to the west. North of the access road, at TF 631 179, virtually nothing remains of the bank, though the ditch continues on the west.
E. Rose (NLA), 26 March 2004.

December 2013. Field Visit.
Site visited following damage report by member of the public.
Sections of the bank on Hardwick Narrows Common (between approximately TF 63062 17632 and
TF 62941 17176) have recently been levelled.
An earthwork bank following the line of this feature has been recorded by the National Mapping Programme as a post-medieval feature relating to drainage and enclosure (NHER 38323). It is also shown on (S1).
D. Robertson (HES), 2 January 2014. Amended A. Cattermole (King's Lynn UAD), 3 July 2017.