So many dolmens and portal tombs were pressed into their legend that the phrase "Dermot and Grania's Bed" became almost a generic folk name, applied to prehistoric monuments in counties far removed from one another. The example at Coolcronaun in County Mayo is one such site, carrying that familiar romantic alias while quietly remaining what it always was: a megalithic tomb of considerable age.

The site is documented in Ruaidhrí de Valera and Seán Ó Nualláin's Survey of the Megalithic Tombs of Ireland, Volume II, covering County Mayo, published by the Stationery Office in Dublin in 1964. De Valera and Ó Nualláin's survey was a landmark project in Irish prehistoric archaeology, systematically recording the portal tombs, court tombs, passage tombs, and wedge tombs spread across the country. A megalithic tomb of this type would typically consist of large upright stones supporting one or more capstones, forming a chamber that once served as a place of burial, probably dating to the Neolithic period, roughly four to six thousand years ago. The folk name attached to the Coolcronaun monument reflects a widespread Irish habit of anchoring mythological narrative to the physical landscape, giving stones and earthworks a human story when their original builders and purposes had long been forgotten.