It sits somewhere in that particular category of Irish antiquity that has been counted but not yet properly examined, acknowledged but not explained. Enclosures of this kind are among the most common prehistoric and early medieval features in the Irish landscape, typically circular or sub-circular earthworks defined by a bank and ditch, sometimes the remains of a ringfort, sometimes a field boundary or enclosure for livestock, sometimes something older and harder to categorise. That Lissanisky has one is not in itself remarkable; that so little has been committed to the record about it is, in its own quiet way, telling.

The townland name itself offers a faint clue. Lissanisky likely derives from the Irish, with "lios" pointing to a fort or enclosure, which suggests the feature may have been visible and recognised long enough to shape the place-name, a process that often happened over many centuries of continuous habitation and land use. In parts of Mayo, enclosures of this type date from the Iron Age through to the early medieval period, roughly the first millennium AD, and were frequently associated with farming settlements. Whether the Lissanisky enclosure fits that pattern, or represents something earlier or later, is not currently possible to say with any confidence.