The arrangement is deliberate, and it is very old. This is a wedge tomb, a type of megalithic burial monument built during the late Neolithic and early Bronze Age, typically characterised by a chamber that narrows and lowers from one end to the other, giving the structure its name. What makes the Drombohilly example quietly remarkable is how intact it remains, sitting in rough pasture on a natural terrace, largely as it was left.

The oval cairn enclosing the tomb measures roughly ten metres north to south and just under eight metres east to west. Within it, the burial chamber is aligned east to west and open at its western end, a common orientation for wedge tombs in Ireland and one that may have carried deliberate solar significance. The chamber itself is modest in scale, around one and a half metres long, widening slightly toward the west where it measures about 1.3 metres across, narrowing to under a metre at the eastern end. It is formed by a backstone closing the east end and a single sidestone on each side. The roofstone is considerably larger than the chamber it covers, spanning 3.2 metres by 2.25 metres at a thickness of 0.3 metres, and it rests across the backstone and the northern sidestone, sloping down toward the enclosed end. The cairn material itself contains inclusions of quartz, a detail worth noting since quartz was frequently used with apparent intentionality at prehistoric funerary sites across Ireland and Britain, though what meaning was attached to it remains a matter of scholarly debate. The structure was documented by Twohig in 1986.