First documented on the 1836 Ordnance Survey map, this enigmatic monument occupied a gentle slope about four kilometres from the River Finn, close to the eastern edge of a byroad. When the OS surveyors encountered it in the 1830s, they found five substantial stones; three standing upright and two fallen, with the tallest reaching about 1.5 metres high and appearing to be partially sunk into the earth.

By the time antiquarian Thomas Fagan examined the site between 1845 and 1848, the configuration had changed somewhat. He observed what he believed to be the remains of a structure measuring approximately 6.1 metres long and between 1.5 to 2.15 metres wide, oriented almost north to south. Only two stones remained upright by then, positioned opposite each other on the eastern and western sides, whilst two others lay prostrate to the north. The standing stones were substantial; the eastern one measured 1.5 metres high, 1.7 metres broad, and up to 0.6 metres thick, whilst its western counterpart stood lower at 0.75 metres high but stretched 1.7 metres in length. The fallen stones were even more impressive, with one measuring 2 metres by 1.15 metres and up to 0.9 metres thick, and the other reaching 2.15 metres by 1.7 metres.

Though some stones were still present when the Ordnance Survey returned in 1904, by 1952 all traces of the Giant’s Grave had vanished from the landscape. Archaeological assessment suggests the monument may have been a megalithic tomb, with Fagan’s two upright stones possibly serving as orthostats flanking a burial chamber or gallery. Without proper excavation or more detailed documentation, however, the true nature of this lost monument remains tantalisingly uncertain, another casualty of time and agricultural improvement that once dotted the Donegal countryside.