The tomb on Slievenaglasha in County Clare is one of dozens that borrowed this romantic association, appearing on Ordnance Survey maps as far back as 1842 labelled 'Dermot & Grania's Bed'. What makes this particular example quietly arresting is not the legend, however, but the accumulated strangeness of its biography: a prehistoric burial monument that was later sheltered under, possibly set on fire, and left in a condition where fragments of its own capstone now lean at odd angles inside the chamber it once sealed.

Wedge tombs are the most numerous megalithic tomb type in Ireland, typically dating to the late Neolithic or early Bronze Age, characterised by a trapezoidal gallery that is wider and higher at the western end and narrows toward the east. This one sits on a south-east-sloping, grass-covered crag within what appears to be an extensive field system spanning several periods of use. The tomb is oriented roughly east-north-east to west-south-west, and when Ruaidhrí de Valera and Seán Ó Nualláin surveyed it for their 1961 Survey of the Megalithic Tombs of Ireland, they found it partly damaged but still legible in its main elements: a north sidestone of fine limestone running 4.5 metres in length, cracked near its western end and worked along its top edge on both sides, and a shorter, more badly broken south sidestone. Two closing slabs seal the western end at slightly differing angles. The antiquarian T. J. Westropp, writing in 1896 and again in 1913, described the structure as 'much injured by fire' and 'partially destroyed', suggesting significant damage around 1880. Earlier still, the Ordnance Survey Letters of 1839 noted the tomb as a place 'under which many poor families have lived', and the collapsed remains of a drystone hut at the eastern end of the monument, which had obscured that part of the chamber entirely, may be the physical remnant of exactly that arrangement.

The tomb sits within rough pasture commanding wide views to the north-east and west. Inside the chamber, loose and broken slabs lean at various angles; some are thought to be fragments of the original capstone, while others appear to be rubble from the later hut that abutted the eastern end. A grass-covered heap of stones to the north of the tomb is likely further collapse from that same structure. An inspection carried out in 1999 found the monument unchanged from the earlier description, its layers of use and damage preserved more or less as de Valera and Ó Nualláin had recorded them nearly four decades before.