The earthwork remains of a large irregular mound measuring c.60m x 68m, and two smaller mounds immediately to the west were seen centred as a group at seen at TQ 7445 7856 in the curve of two watercoures. These mounds form part of a group of similar mounds which are all probably medieval saltern mounds.
The adjacent groups of mounds have been recorded in separate NMR records: NMR Monument Numbers 416699, 1532581 and 1532585.

These and surrounding mounds were mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project.

Saltern mounds are the result of large-scale salt manufacturing where brine was extracted from salt-rich sands and sediments, concentrated and evaporated using process known as sleeching. The discarded waste material from the process built up around the production area into a sizeable mound, often with a hollow in the centred where a hut stood. These medieval saltern mounds are typically described as `floriate' in form because of their irregular lobed formation of dumped waste. They often occur in clusters around former and surviving tidal water-courses within the marsh. There has been considerable reclamation and subsequent sea wall construction since the medieval period which has isolated these sites from the sea.

Many of these mounds were subsequently utilised as sheepfolds, sheep washes and stock refuges in the post medieval period because of their slightly elevated position in the readily flooded marshes.

Roman finds have been extracted from some of these sites, but are believed to be from the lower levels, and not associated with the mounds. Post-Roman flooding and silt deposition has resulted in Roman sites lying typically several feet below the current land surface. (1-4)

<1> Historic England, 2012, National Mapping Programme survey: Hoo Peninsula (Digital archive). SKE32442.

<2> English Heritage, 2013, Hoo Peninsula, Kent. Hoo Peninsula Historic Landscape Project (Bibliographic reference). SKE31432.

<3> RAF, 1953, NMR RAF/82/713 01229 16-FEB-1953 (Photograph). SKE57156.

<4> Spurrell FCJ,, 1885, Early Sites and Embankments on the Margins of the Thames Estuary (Article in serial). SKE53799.

<5> Historic England, 2016, Archive Material (Archive). SKE57167.