A souterrain, to give it its proper context, is a man-made underground structure, typically built during the early medieval period in Ireland, consisting of one or more chambers and connecting passages constructed from dry-stone walling and covered with large capstones. They were dug into the earth and used variously for storage, as places of refuge, or as components of a wider settlement. The Killeens example is one of many such features scattered across Kerry, a county whose landscape conceals a remarkable density of early medieval activity.

Beyond the fact of its existence and its location in the townland of Killeens, detailed information about this particular souterrain remains sparse in the public domain. What can be said with confidence is that souterrains of this type were commonly associated with ringforts, the circular enclosed farmsteads that defined rural settlement in Ireland from roughly the sixth to the twelfth century. Kerry has an unusually high concentration of both ringforts and their associated underground features, partly a reflection of the county's strong early Christian and pre-Norman Gaelic culture, and partly of how much of the landscape has escaped intensive modern development. The specific dimensions, condition, and excavation history of this souterrain at Killeens are not presently available, and any attempt to describe them further would be speculation.