The monument is gone, levelled without record, and nothing remains above the surface. What makes the site quietly remarkable is not what survives but what the sequence of documentation reveals: a monument observed, described, debated, classified, and then found to have vanished entirely within the span of a few decades.

A field report from May 1977 recorded a circular, grass-covered mound of earth and stone, roughly nine metres in diameter and rising to about 1.4 metres in height, positioned on a prominent natural rise with clear views across the surrounding landscape. The stones visible where the surface had eroded were approximately 20 centimetres in diameter. The surveyor noted no trace of a fosse, the external ditch that typically encircles a burial mound, and no trace of a kerb, the ring of stones sometimes laid around a mound's base. A second survey in August 1981 broadly confirmed these dimensions, now measuring the height at 1.5 metres, and suggested that some stones near the base might represent the remnants of a slight kerb. That small disagreement between the two accounts became significant later. When David McGuinness surveyed the site in 2015, the mound had disappeared entirely; the land had been recently ploughed. Working back through the two earlier descriptions, McGuinness concluded that the 1981 suggestion of a kerb was not reliable given the first surveyor's clear statement to the contrary, and that the absence of any surrounding ditch meant the monument should be classified not as a bowl-barrow but as a mound-barrow, a simpler earthen burial monument without the defining encircling earthwork. The classification mattered, even for something that no longer existed.

There is nothing to see at Killagh now. The site's interest lies entirely in what the paperwork preserves: three snapshots of a small, unremarkable-looking mound, each one slightly different, and a final entry confirming its destruction. It is a reminder of how much of Ireland's prehistoric landscape has been quietly erased between one survey and the next.