Monument record TQ 77 NE 1317 - The earthworks of a possible medieval saltern mound can be seen on aerial photographs taken in 1947.

The earthworks of a possible medieval saltern mound can be seen on aerial photographs taken in 1947. This mound is situated towards the northern end of Cooling Marshes and is centred on TQ 7641 7795. The area of the mound is enclosed on three sides by drainage channels and on the northern side by the earthworks of a disused drainage channel that once connected with the others. Mounds such as this represent the discarded waste material from salt manufacture, a process - known as sleeching - in which brine was extracted from salt-rich sands and sediments, concentrated and evaporated. Slaterns could no longer operate once sea walls were constructed converting this area to fresh marsh. These sites sometimes became the focus for later building, although no evidence of this has been discovered here. This site was mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project(1)

<1> Royal Air Force, 1953, RAF 82/713 315-316 6-FEB-1953 (Photograph). SKE58591.

<2> Historic England, Historic England Archive (Archive). SKE58567.