Across Ireland, portal tombs and related megalithic structures, ancient communal burial monuments typically constructed from large upright stones capped by a massive roofstone, were frequently assigned in folklore to the legendary lovers Diarmuid and Gráinne, the couple who fled across Ireland pursued by Fionn Mac Cumhaill. The attachment of their names to prehistoric monuments was a way of accounting for structures whose true origins had long passed out of living memory, and County Leitrim has its own example sitting quietly in pasture about 250 metres south of Lough Scur.

The structure itself is a limestone chamber roughly 4.6 metres long, 3.75 metres wide, and standing about 1.65 metres high. It consists of two portal-stones, two collapsed sidestones, a collapsed backstone, and a large roofstone that has since broken into four pieces. About six metres to the north, two further slabs may represent the remains of a second chamber, though their status remains uncertain. The tomb was recorded by William Copeland Borlase in 1897, appearing in the first volume of his study of Irish megalithic monuments, and was later examined by Ruaidhrí de Valera and Seán Ó Nualláin in their systematic survey published in 1972, which catalogued portal tombs across the country.

Access is straightforward. A small car park sits about 40 metres to the southwest of the monument, and the tomb itself is now encircled by a concrete and stone path that keeps visitors from straying too close to the unstable stonework. The broken roofstone is visible from the approach, giving the structure a slightly collapsed, settled-into-the-earth quality that is not unusual for monuments of this age.