It is a souterrain, a type of structure built during the early medieval period, typically between the seventh and twelfth centuries, consisting of one or more subterranean chambers connected by low crawlways and constructed from dry-laid stone. Scholars debate their precise function, but the leading theories centre on food storage, taking advantage of the constant cool temperature underground, and refuge during times of raid or conflict. Thousands were built across Ireland, yet each one occupies a specific piece of ground, tied to a particular community and a particular moment in time, and the one at Boleyboy is among those that have so far attracted little published attention.

The townland name Boleyboy derives from the Irish, likely containing the element "buaile", referring to a seasonal grazing place or summer pasture, a detail that gestures at the agricultural rhythms of the people who once worked this landscape. Whether the souterrain served a nearby ringfort, a common pairing across early medieval Ireland, or sat at the edge of some other settlement is not currently documented in any publicly available source. What can be said with confidence is that its presence marks Boleyboy as a place of early medieval activity, where someone went to considerable effort to quarry, haul, and carefully position stone underground, for purposes that mattered enough to warrant the labour.