Portal tombs, sometimes called dolmens, are among the most visually distinctive megalithic structures, typically formed by two tall upright stones flanking an entrance, capped by a large flat roofstone. The one at Camcuill, however, presents a quieter and more troubling puzzle: by the time anyone looked for it again, it had apparently vanished.

The tomb was recorded during a survey in 1973, and photographs taken that year show it intact, viewed from the north and from the east. It was documented in Seán Ó Nualláin's authoritative Survey of the Megalithic Tombs of Ireland, Volume V, covering County Sligo, published in 1989. But when the site was revisited in 1993, something had changed. A drainage channel to the north of the monument had been deepened in the intervening years, and the working theory is that either the tomb was destroyed outright in the process, or that spoil, the excavated material piled up during drain clearance, was dumped over it and now buries it entirely. Neither outcome is particularly reassuring. Tomas Kytmannow, writing in 2008, noted the loss.

What makes this site unusual is not dramatic destruction but slow administrative erasure. The 1973 photographs are among the last evidence that the structure existed in any visible form. Whether it still lies beneath the ground, compressed under drainage spoil, or whether the stones were broken up and removed, is not currently known. It is the kind of loss that happens quietly, not through deliberate demolition but through the ordinary business of land management, and it is precisely because such losses are undramatic that they tend to go unnoticed until someone checks the record against the field.