In traditional open pan salt making, large, shallow uncovered pans of brine or sea-water were boiled over oven flues to evaporate the water and recover the salt. Pans during this period were coarse pottery vessels and although the process was highly inefficient in both labour and energy the salt was highly prized.

Quantities of coarsely made local pottery eroding from a cliff on the Lizard were the first indications of a Romano-British salt making industry in Cornwall. Since the initial discovery at Trebarveth a number of other similar sites have been recognised on the Lizard, for instance above Ebber Rocks to the north of Black Head, but not, to date, in other parts of the county.