An assessment of Lidar data carried out by English Heritage in 2009-2012 identified a possible saltern /enclosure / sheepfold.(1,2)

The earthwork remains of an irregular embanked enclosure measuring c.60m x 75m, possibly the site of a former post medieval sheepfold or sheep wick. The site is located at TQ 7386 7817 in the north-eastern corner of a low-lying field within Cliffe Marshes. It is surrounded on two sides by existing water-filled ditches, and the earthwork traces of former, now dry, ditches on the remaining sides. It is possible that this enclosure is the remains of a former medieval saltern mound, the elevated area in the marshes re-used in the post medieval period.
A smaller oval mound (Monument Number: 1532375), also thought to be a medieval saltern mound lies immediately to the north of this site on the opposite side of the field ditch.

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.

This site was mapped from Environment Agency lidar imagery as part of the English Heritage: Hoo Peninsula Landscape Project. (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> Environment Agency, 2001, LIDAR TQ 7278 Environment Agency D0015733 APR-2001 (Digital archive). SKE57158.