The earthwork at Killinardan is thought to represent a section of the Pale, the fortified frontier zone that separated the anglicised settlements around Dublin from the Gaelic territories beyond. Linear earthworks of this kind typically consisted of a raised bank with ditches on one or both sides, constructed to channel movement, deter cattle raiding, and signal, however imperfectly, where one world ended and another began.

The record for this site is slender but specific. Writing in 1939, Hegarty noted remains of a double ditch at Killinardan, identifying it as part of the Pale and observing that its course could still be traced for some distance by a succession of hawthorn bushes growing along it. The hawthorn, a species long associated in Ireland with boundary planting and with a certain superstitious reluctance to disturb, had effectively become the earthwork's memory, preserving its line long after the ditches themselves had silted and softened into the surrounding ground. The Pale as a political and administrative concept was most formally defined in the later medieval period, and its physical boundary, where it existed at all, was never a single continuous wall but a patchwork of ditches, hedges, castles, and agreed limits that shifted over time.

Precise location remains uncertain, and this is not a site with any formal access, interpretation, or signage. Killinardan lies in the southern Dublin area, and anyone with a serious interest in tracing the feature would do well to consult historical Ordnance Survey maps alongside Hegarty's original account before visiting. The hawthorn line, if any portion of it persists, is the thing to look for, a hedgerow that follows no obvious agricultural logic and sits slightly too straight, or slightly too old, to be entirely accounted for by the surrounding landscape.