The structure is a wedge tomb, a type of megalithic burial monument built during the late Neolithic and early Bronze Age, typically consisting of a tapering stone chamber covered by one or more large capstones. This one has been given the name "Dermot and Grania's Bed", a designation shared by dozens of similar monuments around the country. The legend attached to them tells of Diarmuid and Gráinne, the fugitive lovers of Irish mythology, perpetually on the run from the warrior Fionn Mac Cumhaill, and supposedly sleeping in a different stone chamber each night. The name says less about this particular place than it does about how ordinary people, for centuries, made sense of the strange old stones around them.

The tomb itself is modest in scale but carefully preserved by the landscape rather than by any intervention. It measures roughly 3.5 metres in length, with a chamber that narrows from about 1.6 metres at the western end to 1.3 metres at the east, aligned broadly east-northeast to west-southwest. A single sidestone forms the northern wall, with two sidestones on the southern side, and together they support one large roofstone. Faint traces of the original covering mound can still be made out to the north and west of the structure. The site was recorded by Ruaidhrí de Valera and Seán Ó Nualláin in their systematic Survey of the Megalithic Tombs of Ireland, published in 1972, which documented this and comparable monuments across Galway and several other counties. Lord Killanin and Michael V. Duignan had also noted the tomb in their 1967 Shell Guide to Ireland.