A midden is, at its simplest, a refuse heap, the accumulated shells, bones, ash, and discarded objects left behind by people eating and living in a place over time. That description makes them sound mundane, but middens are among the most informative sites an archaeologist can encounter. The layers within them can preserve organic material that survives nowhere else, building a detailed picture of diet, season, trade, and daily life across sometimes thousands of years.

The west of Ireland coastline and its hinterland are home to a number of shell middens in particular, many dating to the Mesolithic and Neolithic periods when communities relied heavily on marine and estuarine resources. The Sligo region sits within a landscape shaped by Atlantic exposure, and the presence of a recorded midden at Culleenduff fits into a broader pattern of early and sustained human activity along this stretch of the west. Beyond its recorded status as a monument, the specific details of date, extent, and excavation history for this particular site are not currently in the public domain.