A midden is, in essence, a rubbish heap, the accumulated shells, bones, ash, and discarded objects that past communities left behind. That unglamorous description belies the archaeological value: middens preserve organic material that would vanish almost anywhere else, and they can reveal with unusual precision what people ate, how they lived, and how long a place was occupied.

Tóin An Tseanbhaile sits in County Mayo, a county whose coastline and islands have been inhabited since prehistory. Coastal middens in this part of Ireland frequently contain dense deposits of shellfish remains, particularly limpets and periwinkles, alongside animal bone and the occasional worked flint or fragment of coarse pottery. The place name itself is suggestive: "tóin" carries a colloquial earthiness in Irish, and its attachment to "the old settlement" implies local memory of a habitation that had already become ancient by the time the name was coined. That layering, a midden within a named old place, points to a site with more than one period of human activity folded into it.