Monument record TQ 77 NE 1340 - ?Medieval saltern mound, Halstow marshes

The earthwork remains of a possible medieval saltern mound can be seen on aerial photographs taken in 1953. This mound, centred on TQ 7756 7813, is situated on Halstow marshes at the site of Shade House (see NMR 1531466), which appears to have been built on top of the mound.

Shade house sits within an enclosure circa 100m by circa 45m that is defined by drainage channels. Most of this area was occupied by the mound although there is a gap at the eastern end (at TQ 7759 7814). This mound was also the location for a post-medieval sheep fold (see NMR 1531470). Smaller mounds to the east (TQ 7762 7816) and to the west (TQ 7751 7810) are separated from the main mound by two of these channels and they may have originally been part of the larger mound. There is a third mound to the west at TQ 7748 7810. The smaller mounds had been levelled by 1970.

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. The depressions at the eastern end may mark the site of the original building. Sites such as this could no longer operate once sea walls were constructed converting this area to fresh marsh but, as Shade House and the sheep fold indicate, these sites often became the focus for later building. These earthworks were mapped from aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project.(1-2)

<1> RAF, 1953, RAF 82/713 238-239 6-FEB-1953 (Photograph). SKE58819.

<2> 1970, MAL 70086 39-40 13-NOV-1970 (Photograph). SKE58820.