Access to Lambay, which lies roughly five kilometres off the north Dublin coastline, is tightly restricted, which means the site remains largely unknown outside archaeological circles. The combination of the two cairns, one stacked against the other in a way that suggests different phases of construction or use, gives the monument an odd, almost layered quality that rewards attention.

The circular cairn is modest by any measure, around three and a half metres in diameter and just sixty centimetres high, a low dome of heaped stone that could easily be overlooked. It rests against the western end of a considerably more substantial oblong cairn, flat-topped and elongated, measuring over twenty metres in length, more than sixteen metres wide, and standing three metres tall. A cairn, in the simplest terms, is a deliberate pile of stones raised over a burial or as a marker in the landscape, and the two here together suggest a site with some complexity in its origins. The monument was noted by Gabriel Beranger and recorded on Duncan's map of 1821, which gives some indication of how long it has been recognised as a feature worth documenting. More recent archaeological work by Gabriel Cooney, published in 2009, has set the site within a broader understanding of Lambay's prehistoric landscape.

Lambay is a private island, owned by the Revelstoke branch of the Baring family since the early twentieth century, and landing without permission is not straightforward. Those with legitimate access should look for the cairns on Tinians Hill in the island's interior, where the rock outcrop on which the monument sits becomes visible as the ground rises. The flat-topped upper surface of the larger cairn and the smaller circular mound at its western edge are best appreciated from close up, where the deliberate shaping of the stone becomes clearer. The surrounding landscape of the hill offers context, as the cairns occupy a position that would have given their builders a commanding view over much of the island.