The pairing comes from the medieval legend of Diarmuid and Gráinne, fugitive lovers who, according to folklore, slept in a different prehistoric monument each night as they fled across the country. The name attached itself so widely to ancient tombs that it became, in effect, a folk category of its own, a way of making sense of these strange stone chambers through the only narrative framework that felt equal to their age and mystery. The example on Inis Mór, sitting along the western end of the island's central ridge in the area known as Corruch, is one of the more compact of these monuments, and one of the better preserved.

What stands here is a wedge tomb, a type of megalithic burial structure built during the late Neolithic and into the Bronze Age, typically characterised by a gallery that tapers from a wide, open end towards a narrower, closed rear. This one measures 2.5 metres in length, opening to 1.8 metres at its western end and narrowing to 0.8 metres at the back, where a single closing slab seals the chamber. The gallery is oriented ENE to WSW, with three overlapping capstones forming the roof. Along the southern exterior runs a closely set double wall of upright slabs, a feature that gives wedge tombs some of their distinctive boxy solidity. Faint traces of the original covering mound can still be made out to the south of the structure. The monument was documented in detail by Ruaidhrí de Valera and Seán Ó Nualláin in their 1972 survey of megalithic tombs in the west of Ireland, and it has since been taken into state ownership as a protected National Monument.

The tomb sits in the Corruch subdivision, towards the western end of Inis Mór's long central limestone ridge. Visitors to the island who move away from the more frequented sites around Dún Aonghasa will find the landscape here quieter, the ground rougher, the sense of the island's deep prehistory correspondingly stronger. The monument is modest in scale, and easy to overlook if you are not specifically looking for it, but the preservation of its roofing slabs and double walling makes it a clear and legible example of its type.