It is a designation that appears repeatedly across Ireland, attached to caves, megalithic tombs, and other sheltered recesses in the landscape, and it points to one of the most persistent strands of Irish mythology: the elopement of Diarmuid and Gráinne. In the tale, the lovers flee across Ireland pursued by Fionn Mac Cumhaill, sheltering each night in a different wild or remote spot. The name, wherever it appears, suggests that local memory once mapped this ancient story onto the physical world, identifying particular places as stages in that long, fateful flight.

The cave at Gleniff sits in the Dartry Mountains, a landscape of limestone escarpments and steep valley walls that lends itself naturally to such associations. Its appearance in Seán Ó Nualláin's 1989 survey of the megalithic tombs of County Sligo is a reminder that the folklore attached to prehistoric and natural features often outlasts any precise understanding of their origin or function. Ó Nualláin's survey, a systematic county-by-county inventory of Ireland's megalithic monuments, recorded the cave and its name as part of a broader effort to document what survives in the Sligo landscape, whether ancient architecture or the oral traditions that accumulated around natural features over centuries.