It is not large, roughly 12.7 metres east to west and 11 metres north to south, and rising no more than 2.5 metres at its highest point, but what makes it worth pausing over is the evidence of interference. At some point, someone dug into it. A trench about 1.5 metres wide and 5 metres long has been cut through the centre and north side, destroying the fosse and the mound's northern profile in the process. The fosse, a shallow surrounding ditch of the kind commonly used to define and protect prehistoric earthworks, survives elsewhere around the mound, reaching a depth of 1.4 metres on the uphill southern side where soil pressure would have been greatest.

Barrows are among the most widespread ancient monument types in Ireland, typically serving as burial mounds raised over the dead during the Bronze Age, though some date earlier or later. This particular example sits at the head of a south-east to north-west valley, a topographical position that may have been chosen deliberately, given the tendency of prehistoric communities to site funerary monuments at prominent or liminal points in the landscape. The partial excavation, informal and unrecorded rather than any organised investigation by the look of the trench dimensions, has left the interior exposed but unresolved. Whatever was originally deposited within the mound, if anything survives, remains unknown. A causeway or spoil heap about 1.5 metres wide sits in the fosse at the south-west, likely the result of whoever dug the trench moving material outward. About 150 metres to the north-east lies a rath, a circular earthen enclosure associated with early medieval settlement, suggesting this corner of Lacken Hill was in use across a considerable stretch of time.