Saltwick Nab was a site of alum quarrying between 1650 and 1791, the red colouring indicates shale has been burned which is part of the alum making process.

An alum house existed in later years, although its though that initially the alum liquor was  taken to South Shields for processing. The remains of a stone ramp exist on the shore, which may have been used to get carts on and off the Nab.

The flat area inland of the Nab has some remains of buildings and wooden pits, although the whole area has been so heavily eroded since it was worked its now difficult to interpret, it is however much more apparent on the first edition OS maps.