A prehistoric burial mound, a barrow, once occupied a low rise on the boundary between the townlands of Tanrego West and Carrownacreevy. By the time anyone thought to measure it carefully, it was already going. By the time anyone returned to check, it was gone.

Barrows are among the oldest humanly constructed features in the Irish landscape, typically earthen mounds raised over the remains of the dead during the Bronze Age, though they vary considerably in form and date. This one was modest but measurable. The Ordnance Survey's six-inch map of 1837 recorded it as a small circular enclosure, meaning it had survived long enough to be cartographically noted at a moment when Ireland was being systematically mapped for the first time. Over a century and a half later, a field assessment in 1994 found a circular platform roughly nine metres in diameter, rising to about 1.35 metres at its northern edge and 1.55 metres at the south, defined by a scarp, the abrupt slope marking the edge of the mound. There were faint traces of a possible bank along the upper southern edge, around a metre wide, though no fosse, the surrounding ditch that commonly accompanies such earthworks, could be identified. Notably, the mound's perimeter had been absorbed, at least along its western to north-eastern arc, into a field boundary that marked the division between the two townlands, suggesting it had been pressed into agricultural use long before anyone thought to document it formally.

That incorporation into a field boundary was likely part of what undid it. The monument has since been levelled entirely, and there are no remains visible at ground level today. What the 1837 map recorded, and what the 1994 fieldwork measured, exists now only in those documents.