Its popular name carries the weight of one of medieval Ireland's most enduring love stories, that of Diarmuid and Gráinne, the ill-fated couple whose flight from the wrath of Fionn Mac Cumhaill left its mark on dolmens, caves, and earthworks the length of the country. The name is folklore rather than archaeology, a habit of attaching romantic legend to ancient monuments whose true purpose had long been forgotten by the communities living beside them.

What actually survives at Killevny is a ring-barrow, a form of prehistoric funerary monument typically consisting of a low central mound enclosed by a circular ditch, known as a fosse, sometimes with an outer bank beyond it. This example measures roughly 22.6 metres in diameter overall, with a flat-topped raised area at its centre about 10.8 metres across and no more than 0.2 metres high at its greatest extent. It is poorly preserved and partly obscured by furze and hawthorn growth, giving it a shaggy, neglected appearance. Traces of an external bank survive on the south-west to west arc. When the site was inspected in February 1985, an old field boundary abutted it to the south-east, and a narrow drain ran northward for about seven metres from the northern edge; aerial imagery from 2019 shows the field boundary has since been removed. The monument does not stand in isolation. A bowl-barrow lies approximately 30 metres to the south-east, and de Valera and Ó Nualláin, writing in 1972, identified a possible third barrow roughly 25 metres to the south-south-west, suggesting this corner of Galway once held a small cluster of prehistoric burial monuments whose full extent remains only partially understood.