It once formed the backbone of a fish palace, the name given to shore-based facilities used in the early modern period for processing pilchards and other oily fish, typically involving large wooden presses that squeezed train oil from the catch. The wall itself is substantial, running over twenty metres in length and standing three and a half metres high, with a thickness of nearly one and a half metres. What makes it legible as an industrial structure, rather than a field boundary or a ruin of some domestic building, is what is built into its faces.

On both the east and west elevations, twenty-nine small lintelled niches, each only about eighteen centimetres high and fifteen wide, are set into the stonework at roughly eighty centimetres above ground level. Above these, at just under two metres, eleven larger rectangular beam holes perforate the wall entirely. Together, these features tell the story of the press mechanism: the lower niches likely seated timber elements that formed a framework, while the beam holes carried the horizontal press beams that were levered down with enough force to extract oil from packed layers of fish. It is a mundane piece of industrial engineering, but the wall preserves its internal logic with unusual completeness. The structure stands just east of Sherkin's Franciscan friary, and the proximity of the two is a reminder that the island was once a functioning economic community, not merely a spiritual outpost. The fish palace was documented by Went in 1946, placing it within a broader survey of the Irish pilchard industry that identified similar processing sites along the south-west coast.