It does not end tidily; it simply meets the sea, as though the land it once divided has quietly disappeared beneath it. The wall is only a few centimetres above ground level now, between twenty and forty centimetres at most, and much of it is buried under accumulated seaweed and rubbish, making it awkward to examine properly. What is visible suggests a structure built from sandstone slabs and smaller cobbles, roughly three metres wide, in the manner of a drystone field boundary, where stones are laid without mortar and rely on their own weight and arrangement for stability.

What makes this wall genuinely unusual is where it comes from rather than where it ends. It appears to emerge from beneath an exposed peat bank standing about eighty centimetres high, meaning the wall predates the formation of that peat, or at least was already in place when the bog began to accumulate over it. Peat forms slowly, over centuries and millennia, as waterlogged organic matter builds up layer by layer, so a structure buried beneath it is by definition old, though the notes do not pin down a precise period. The cove sits on the eastern side of Achill Sound, the narrow channel separating Achill Island from the Mayo mainland, a stretch of coastline that has been farmed and settled since prehistory. Two further walls lie to the west, one roughly ten metres away and another about forty metres beyond that, suggesting this was once a patterned agricultural landscape, fields laid out close to the shore, now largely swallowed by bog and tide.