When inspectors returned to the site in 1999, the structure had been swallowed entirely by scrub and overgrowth, leaving no trace visible from the surface. It is not destroyed, as far as anyone knows. It is just lost, somewhere in the undergrowth, with its dimensions on record and its location a matter of educated guessing.

The tomb belongs to a type known as a wedge tomb, the most numerous category of megalithic monument in Ireland, built during the late Neolithic and into the Bronze Age. The defining characteristic of the form is a trapezoidal chamber, wider and taller at the front than at the rear, typically orientated toward the south or south-west. The Gragan example was recorded in detail by Ruaidhri de Valera and Seán Ó Nualláin as part of their Megalithic Survey of Ireland, published in 1961. At that time the structure was considered moderately well-preserved despite the overgrowth. The chamber measured roughly 2.25 metres in length, with a southern sidestone standing erect at a height that rose from 0.8 metres at the rear to 1.25 metres at the front, and a northern sidestone leaning outward at approximately 45 degrees. The backstone, 1.25 metres long and 0.8 metres high, had both its upper corners removed and sat flush against the northern sidestone, though a small gap remained between it and the southern one. Three small slabs found within the chamber may have been the remains of a capstone. Around the chamber, seven surviving slabs of an outer wall formed a slightly larger wedge shape, and a roughly circular cairn, a low mound of heaped stone originally used to seal and define the monument, extended to about 8 metres in diameter, rising to no more than half a metre at its highest point. The whole structure was orientated toward the south-west, in keeping with the broader tradition for this tomb type.

What makes the Gragan tomb quietly compelling is precisely this combination of precision and absence. It exists in considerable detail on paper: stone by stone, measurement by measurement, with a photograph taken during the original survey. Yet since 1999, no one has been able to put their hand on it.