The whole structure has tilted southward over the millennia, giving it a slightly precarious air, yet the essential architecture remains legible: two tall portal-stones and a door stone marking the entrance to the northeast, a narrow rectangular chamber running northeast to southwest, and two overlapping roofstones laid across the top. The chamber itself is modest, roughly two metres long and under a metre wide, its sides and back each formed from single upright stones. The entire construction sits within a low oval mound measuring around ten metres by eight, the earthwork that would once have given the monument its full visual presence in the landscape.

Portal tombs are among the most visually striking of Ireland's Neolithic burial monuments, characterised precisely by those paired portal-stones flanking the entrance and a capstone or roofstones raised above the chamber. They date broadly to the fourth millennium BC. The Arderrawinny example was documented and catalogued by Ruaidhrí de Valera and Seán Ó Nualláin as part of their county-by-county survey of Irish megalithic tombs, published in 1982, which brought together detailed field measurements and observations for Cork, Kerry, Limerick, and Tipperary. That survey remains a foundational reference for understanding the distribution and construction of these monuments across the south of Ireland. The cliff backdrop at Arderrawinny is an unusual setting; most portal tombs command more open ground, and the sense here of a structure tucked against living rock adds something quietly odd to an already ancient scene.