NHER 27909 (Monument record) - Earthworks of medieval salterns

June 2003. Norfolk NMP.
Two sub-rounded mounds are visible (S1) centred on TF 6294 2118 and TF 6291 2109. The mounds have maximum diameters of 65m and 71m. These are almost certainly medieval saltern mounds, formed by piles of waste sand during salt processing. They are part of a large group of mounds on the former saltmarsh to the east and north of King’s Lynn.
M. Brennand (NMP), 24 June 2003.

February 2018. Earthwork Survey and Trial Trenching.
Evaluation of proposed development site to north of Greenpark Avenue.
Both of these two earthwork mounds fell partially within the proposed development area. An initial topographical survey demonstrated that both mounds still survived, with subsequent trial trenching confirming that they were likely to comprise filtration waste from salt production. The northernmost mound contained a concentration of burnt material and fragments of what was probably lining from broken-up brine-boiling hearths. The southern mound was associated with two clay-lined features. Neither produced any dating evidence.
See NHER 66860 for further details.
P. Watkins (HES), 17 April 2023.

February-March 2019. Excavation.
This final phase of archaeological mitigation prior to the development of the site north of Greenpark Avenue saw further investigation of both these mounds. The southern mound (Saltern 5) revealed significant remains associated with salt production, include a hearth and a number of features likely to represent the surviving elements of filtration units. Archaeomagnetic dating of the heath suggested it had last been fired between 870 and 1050 AD, which was broadly consistent with two Late Saxon/early medieval radiocarbon dates of 1023-1154 cal AD and 1030-1155 cal AD obtained for material from heath waste within the upper levels of the saltern. A small number of Late Saxon pottery sherds were also recovered.
See NHER 66860 for further details.
P. Watkins (HES), 17 April 2023.