The piece is an incomplete hood moulding, the decorative arched frame typically placed above a door or window in medieval and post-medieval stonework, and it measures roughly 75 centimetres long and 15 centimetres wide. What makes it particularly arresting is a carved figure at its terminal end that may be a sheela-na-gig, one of the enigmatic grotesque female figures found on churches and castles across Ireland and Britain, whose precise purpose has long divided historians. The moulding also bears an inscription, though the full text is lost along with the missing sections of stone.

The origins of the fragment are genuinely uncertain, and that uncertainty is itself revealing. Local tradition holds that the stone came from Moortown Castle, though no further detail survives to pin that account down. A competing possibility, and perhaps a more tantalising one, is that the moulding never left its original setting at all. The Civil Survey of 1654 to 1656, a detailed administrative record compiled in the aftermath of the Cromwellian wars, noted the presence in Garestowne of what it called 'one stone house thatcht commonly called the Colledge,' suggesting that a substantial stone structure of some local standing once occupied this part of the village. If the hood moulding is indeed in situ, then the present house may have been built around or against the remains of that earlier building, quietly absorbing a medieval or early modern fragment into its fabric.

Garristown is a small village in north County Dublin, and the house in question sits roughly 65 metres east of Garristown Church and its associated graveyard. The moulding is set into the gable rather than displayed, so it rewards attention rather than announcing itself. Visitors approaching from the church will find it on the southern face of the building. Because it is incorporated into a private dwelling, there is nothing to enter and no formal access to arrange; the fragment is visible from the exterior. The inscription, partially legible, and the possible sheela-na-gig terminal are best examined on a dry day with good light falling on the stonework.