NHER 37404 (Monument record) - Medieval salt production site, medieval and post medieval pottery finds

October 2002. Trial Trenching.
Evaluation of land at former Queen Mary's Nursing Home, London Road. Contexts 1-90 used.
Revealed dumped waste material and three clay lined pits associated with medieval salt production, notably the filtering of seawater. The waste material from the salt production formed mounds which were later incorporated into the town's defences during the later 13th century.
Finds recovered included medieval brick and tile, medieval and post-medieval pottery and post-medieval clay pipe, .
See report (S1) for further details. The results of this work are also summarised in (S2).
J. Allen (NLA), 10 February 2003. Amended by P. Watkins (HES), 19 May 2015.

September 2003-March 2004. Strip Map and Sample Excavation.
Topsoil stripping for building plots undertaken under archaeological supervision followed by excavation of exposed features. Contexts 100 to 315.
This work revealed extensive evidence for medieval salt production, including 12th- to 13th-century pits, filter units and hearths. The dating of saltworking activity to the 12th and 13th centuries is based upon archaeomagnetic dates obtained from the twin hearth and a dumped deposit of pottery overlying the hearth area.
These investigations revealed the first plan of a 12th-13th century saltern in Norfolk. It is possible an earlier phase of salt-production may exist within the vicinity but nothing earlier was observed and no connection could be made with the salterns mentioned in the Domesday Survey.
The techniques of salt-winning in the medieval period were different from those of the prehistoric and Roman periods. The Roman techniques involved the heating and evaporation of seawater concentrated in pools with the sediment being allowed to settle in clay-lined tanks. The medieval method involved salt-rich mud being collected from the foreshore and washed through peat or turves in filtration units resulting in large quantities of waste silt which was heaped up to create mounds that are often still visible.
The end of the salt-making phase was indicated by the construction of the town walls, thought to be around the middle of the 13th century.
See draft publication (S3) for further details. See also assessment report (S4) and updated project design (S5).
J. Allen (NLA), 6 April 2005 and S. Howard (NLA), 3 August 2010. Amended by P. Watkins (HES), 19 May 2015.

A combined archive comprising material from both phases of archaeological work at this site has been deposited with the Norwich Castle Museum (NWHCM : 2017.485).
P. Watkins (HES), 27 May 2019.