The earthwork remains of an irregular mound thought to be a medieval saltern mound located on the edge of a low-lying field in Cliffe Marshes. The mound lies adjacent to a watercourse in the marsh and has the dry earthwork traces of a further former watercours curving around the mounds western side. 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. This site was mapped from Environment Agency lidar imagery as part of the English Heritage: Hoo Peninsula Landscape Project.