What is exposed there is a midden, a layered deposit of domestic waste left by people who lived and ate along this shoreline, and within its eroding section face lie winkle and limpet shells, charcoal fragments, fish bone, and pottery sherds spanning the nineteenth and early twentieth centuries. Stretched across roughly twenty metres of cliff edge, the site sits around 260 metres north-north-west of the island's harbour, where the sandy beach gives way to a rockier foreshore. The ground above is level and grassy, with faint traces of old cultivation ridges still legible in the turf.

The midden was noted, briefly and imprecisely, by the antiquarian T. J. Westropp in 1911, but a proper stratigraphic examination came much later. When archaeologists studied the exposed cliff section in detail, they recorded four distinct layers. Below the modern topsoil came a half-metre band of mid-brown sand dense with shells and charcoal, along with pottery and a heavily encrusted iron nail probably dating to the nineteenth or early twentieth century. Beneath that lay a thinner layer of orange-brown sand with fish bone but almost no shell. It was at the interface of this layer and the underlying glacial till, the dense pale-yellow boulder clay deposited during the last ice age, that something unexpected appeared: a tiny barbed and tanged arrowhead of black chert, a fine-grained flint-like stone that can be worked to a very sharp edge. The arrowhead, prehistoric in type, measures only thirteen to fifteen millimetres in length and three millimetres at its thickest point, with careful pressure flaking visible on both faces. Its tang and barbs, the projections at its base that would have fixed it to a shaft, were already broken when found, though the notches marking where they had been are still clear. Dr Adrian Phillips of Trinity College Dublin identified the chert as comparable to material from the Ballytoohy Formation near the island's lighthouse. The arrowhead may have shifted from its original position due to differential erosion between the softer overlying sand and the harder boulder clay beneath it, so its precise chronological context within the sequence is uncertain. It is now held in the National Museum of Ireland in Dublin, registered as NMI 2006:83.