The earthworks of a possible medieval saltern mound can be seen on aerial photographs taken in 1947. This mound was situated near the coast on Hoo Marshes, south of Damhead Creek. A depression at its western end may be the site of the original building. These mounds 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. Sites such as this could no longer operate once sea walls were constructed converting this area to fresh marsh. The mound has since been levelled by the construction of Kingsnorth power station. This site was mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project.