Nobody is entirely sure what it is. That particular combination, an earthwork of clear deliberate construction and genuinely uncertain purpose, is rarer than it might sound.

The bank is modest in scale but precise in form: roughly 1.8 metres wide at the top, 4.1 metres at the base, and standing about 0.8 metres high, enclosing a muddy interior that sits at much the same level as the surrounding inch, the old Irish term for low-lying riverside meadow, often prone to flooding. It sits immediately east of the Awbeg's own low earthen bank, next to a weir at a narrow point in the river. The structure appears on Ordnance Survey six-inch maps from both 1906 and 1937, drawn there as an arc running north to south-southeast, which at least confirms it was visible and considered worth recording across several decades. The southern half is stony and largely obscured by trees; the northern half is slightly lower and more open. A comparable feature exists at Carrigacooleen, not far away in the same county, which raises the possibility that both belong to some locally practised form of construction, perhaps connected with water management, fishing, or land enclosure, though no firm conclusion has been reached about either.