At roughly nine and a half metres across and less than a metre high, it is the kind of thing a passing walker might dismiss as a natural hump in the field, or a farmer's convenient dumping ground. In fact, both readings contain a grain of truth, which is what makes it interesting.

The structure at Cúil An Bhuacaigh is a cairn, a mound built from stones rather than earth, a form of monument found across prehistoric Ireland and typically associated with burial or territorial marking. This one measures 9.5 metres north to south and 8.7 metres east to west, with a maximum height of 0.8 metres. Its centre is noticeably depressed, a detail that often points to antiquity, whether from the collapse of an internal chamber or from disturbance over centuries. The eastern side sits higher than the rest, and the reason recorded for that imbalance is practical rather than ceremonial: field clearance stones have been thrown onto it, the residue of generations of farmers tidying their land by adding to what was already there. It is a small but telling detail, a prehistoric monument quietly absorbing the agricultural labour of the intervening millennia, its original profile altered by the very landscape it has always sat within.