Embedded within the graveyard's perimeter is the surviving wall of a medieval building, stretching some 18.5 metres on a north-east to south-west alignment and still standing to a height of around two metres. Seven narrow lights, each roughly half a metre tall and a quarter of a metre wide, punctuate the stonework at intervals. These are first-floor openings, meaning the ground level outside has risen over the centuries, burying the building's lower storey beneath it. Most telling of all is the doorway, its elliptical head formed from two pieces of dressed limestone, barely visible above the present ground surface and sheltered by a relieving arch, the kind of secondary arch built above a doorway or opening to divert the weight of the wall away from the lintel below.

The wall sits inside Wexford's medieval town defences, close to St. Selskar's, itself a church with deep medieval roots. The building it belonged to has not been conclusively identified, but the fabric of the wall tells a layered story. The original medieval stonework, with its small blocked or brick-altered lights, was at some later point raised upward and given two additional floors of larger windows set beneath flat brick arches, a detail that places that later intervention firmly in the post-medieval period, when brick became a more common building material in Irish towns. The wall was first formally noted and recorded by Catherine McLoughin, whose observation brought a structure hiding in plain sight within a functioning graveyard into the archaeological record.