Workings in this area comprised of exploitation of naturally-occurring salt from underlying Triassic rocks that are exposed along the Wych Brook in the north-eastern part of the area. These form part of similar deposits occurring though on a much larger scale in Cheshire at Nantwich, Northwich and Middlewich.
Exploitation during the medieval period is indicated by the salt pit or (salinae) valued at 24s recorded in the Domesday survey of 1086 in the manor of Burwardestone, possibly the same one as that noted as being in the possession of Haughmond Abbey in 1291 at Wiche in Iscoyd.
Salt was an important commodity in the earlier Middle Ages, being regulated by a system of tolls, which accounts for its appearance in early documentary sources, the place-name element -wich being derived from the Old English wic (‘trading settlement’, itself derived from the Latin vicus) which was often applied to salt-producing settlements.
By contrast, little appears to be recorded about salt working in the area at later periods though Thomas Pennant refers to a brine spring and salt works near Sarn Bridge over the Wych Brook in his "A Tour in Wales" published in 1794 and there is some evidence to suggest that the Upper and Lower Wych Salt Works were in operation in the 1830s.
Apparantely there is a brine pit about 7 metres in diameter still to be seen at Lower Wych, although on an os map it seems to be on private land so unfortunately it can't be seen.
Also one of the local farms still carries the name Brine Pit Farm.
For more information visit:Cheshire History: Salt