What makes it quietly significant is what local tradition insists lies beneath it: a souterrain, one of the dry-stone underground passages or chambers that early medieval communities in Ireland used variously for storage, refuge, and purposes that are still debated by archaeologists. The mound itself is modest, roughly twelve metres across in either direction and only about forty centimetres high, with a single upright stone slab protruding from its southern edge. Its northeastern side blurs into what appears to be the remnant of a levelled field fence, which means the feature has been partially absorbed into the agricultural landscape over centuries, its edges softened by routine land management.

No excavation appears to have confirmed the presence of a souterrain here, and the attribution rests on local oral tradition rather than exposed stonework or recorded investigation. That tradition is given some weight by what lies roughly a hundred and fifty metres to the southwest: a rath, the circular earthen enclosure typical of early medieval Irish settlement, which has its own confirmed souterrain. A rath with an associated underground passage is a well-documented pattern across Ireland, and the proximity of a second possible souterrain on the same ridge suggests this small area of Mayo may once have supported a more substantial cluster of activity than the present landscape implies. The upright slab still visible at the mound's edge could be purely incidental, a remnant of the field system rather than structural evidence of anything below, but it is the kind of detail that keeps the question open.