A midden, in the most straightforward sense, is a prehistoric refuse heap, the accumulated shells, bones, and discarded matter left by communities who gathered food from the sea and shore over generations. What looks like a patch of disturbed earth or a pale smear in a riverbank can, on closer inspection, turn out to be a compressed record of how people ate, traded, and lived thousands of years before written history.

Culleenamore itself sits within one of the most archaeologically dense landscapes in Ireland. The wider Sligo bay area and the slopes of Knocknarea are associated with Neolithic and early Bronze Age activity, and shell middens along this coastline have long interested archaeologists working to understand the dietary and seasonal habits of Ireland's earliest coastal communities. Middens of this kind frequently contain the remains of oysters, limpets, and periwinkles alongside animal bones and occasionally fragments of pottery or worked flint, each layer offering a kind of compressed timeline of repeated human presence at a particular spot on the shore.