“It is situated on the shores of the bay, which takes its name, and contains several good shops, two or three public houses, a church, and chapel, a salt work, and a small silk manufactory.”1
On the eastern boundary of Cave’s Marsh, close to the wall running along Sea Road, are the part remains of what was once an elaborate system for producing salt on a large scale ( “a considerable salt-work”).2 In the days before refrigeration, large quantities of salt were needed to preserve perishable foods through salting, drying and pickling and the production of salt in ‘salterns’ was, at one time, a common activity in Ireland and Britain.3
The Yellow Walls’ saltern existed from 1770 to 1837 and was located on the far side of Sea Road on a site now largely occupied by Pope John Paul’s National School.4
The production process involved channelling salt water from the estuary into a lagoon at the estuary end of the green and, after extraction of the salt, routing it back to empty into the estuary. The channels or ‘canals’ are prominent on maps from the late 19th/early 20th century as shown below.

Salt Works’ channels shown in late 19th/early 20th century map. © Ordnance Survey Ireland/Government of Ireland.5
No trace of the lagoon or saltern itself remains but the channels are still identifiable today.
By closing the lagoon off and trapping the water, it could in theory evaporate off leaving the salt behind. The Irish climate, however, is not warm enough to produce the degree of evaporation needed and so the practice of evaporating the sea water in heated iron pans was used. The final stages of drying involved putting the wet salt into wooden moulds which were placed in a warm room until the salt dried and set in hard blocks.3
Sources
1. Fraser, James. A hand book for travellers in Ireland:descriptive of its scenery, towns, seats, antiquities, etc. with various statistical tables also outline of its mineral structure, a brief view of its botany, and information for anglers. W. Curry, Jr., 1844.
2. Reports from Commissioners: Eighteen Volumes, Irish Fisheries; Herring Fishery, Vol XXII, 1837.
3. Muir, Richard. Landscape Encyclopaedia. Windgather, 2004.
4. Malahide Historical Society Newsletter, December 1994.
5. Ordnance Survey Of Ireland 25″ Map: online. Reproduced under licence from Ordnance Survey of Ireland; Licence No. NE 0000414.