Shell middens, the layered refuse heaps left by communities who ate shellfish in quantity, are among the more unglamorous but genuinely informative archaeological features a site can offer. They preserve organic material that rarely survives elsewhere, providing evidence of diet, season, and settlement patterns across long stretches of time. This one, located some 50 metres northeast of the early medieval church site of Cill Ghobnait, was circular in plan, roughly 11 metres across and approximately 3 metres deep, and composed primarily of periwinkle and limpet shells mixed with animal bones.

The midden's depth alone suggests it was not the product of a single season or generation. Its position close to Cill Ghobnait, a site associated with early Christian activity on the island, raises questions about continuity of occupation and the relationship between religious settlement and everyday subsistence. None of those questions can now be fully answered, because in 1974 the midden was completely removed and used as road dressing on the island's main road. The shells and bones that had built up across what may have been centuries were spread beneath tarmac or gravel, their archaeological content lost entirely. It is the kind of loss that was not unusual in that era, when the practical needs of small, under-resourced communities often took precedence over the preservation of features whose significance was not always immediately legible.