The sea is eating into an earthen bank, and in doing so it has exposed something that was never meant to be seen again: a compact horizontal layer of black soil, studded with oyster shells, periwinkles, and limpets, lying just below the surface of the ground. It is only 1.4 metres long and 25 centimetres deep, but it is a midden, the accumulated food waste of people who once sat here and ate shellfish, discarding the evidence in a pile that eventually became buried under the earth.

A midden is, in the most literal sense, a rubbish heap, but archaeologists prize them precisely because people threw away what they used and consumed every day. Shell middens like this one are found along Irish coastlines from the Mesolithic period onwards, representing thousands of years of shellfish gathering and eating. The layer here, interspersed with tree and shrub roots, sits with its upper surface just a quarter of a metre below the present ground level, suggesting it was covered over relatively quickly or has been protected by vegetation over time. What makes the site at Monteensudder quietly unusual is that it does not stand alone: a second shell midden lies just 1.5 metres to the north-east, meaning that whoever used this shoreline returned to it repeatedly, or that a community gathered here over a sustained period, leaving behind two distinct deposits within a few paces of each other. Both are now visible only because the bank that concealed them is crumbling into the sea.