An assessment of aerial photographs carried out by English Heirtage in 2009-2012 identified a possible saltern (salt producing site).(1,2)

The earthwork remains of a large irregular mound measuring 30m x 43m, seen at TQ 7384 7826 within Cliffe Marshes thought to be a medieval saltern mound. This was mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project.

These 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. (3)

<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.