It emerges from the base of a peat-face roughly a metre and a half high, running from east-north-east to west-south-west, built from small stones with intermittent upright slabs. In isolation, it sounds unremarkable. The date attached to it is not.

Radiocarbon dating of willow twigs recovered from the base of the wall returned a result of 4760±100 BP, meaning before present, which places its construction somewhere around 2800 BCE, deep in the Neolithic period. At that point, the monument now known as Newgrange had already been standing for several centuries. The wall sits in the Imlagh Basin at the northern end of Valentia Island, and was built directly onto a thin layer of Phragmites peat, the kind formed by common reed in wet, low-lying ground. That detail matters: it tells us something about the landscape those early farmers were working with, ground that was already boggy and marginal, yet evidently worth enclosing or dividing. Over the millennia, peat accumulated on top of and around the structure, preserving it while rendering it invisible. What survives today is poorly preserved, the wall having lost much of its original form, but what little remains is enough to confirm that people were actively managing and partitioning this corner of south Kerry at a time when writing, in Ireland, was still roughly three thousand years away.