The mound measures just over three metres across and rises no more than 20 to 30 centimetres at its highest point, the kind of feature a visitor could easily pass without a second thought. What lies within it, though, points to a layer of activity on this island that predates its famous early Christian associations entirely.

Burnt mounds are among the most common prehistoric site types in Ireland, typically understood as the residue of repeated episodes of heating stones in fire and plunging them into water-filled troughs, most likely for cooking, bathing, or industrial processes. The tell-tale material is always the same: shattered, fire-cracked stone discarded into a heap alongside scorched organic matter. This particular mound came to light in 2001, during an assessment carried out ahead of conservation works on the island. Rabbits had already begun to disturb it, and their burrowing exposed fragments of burnt and fire-cracked sandstone within a rich organic silty clay. Alongside the stone were a couple of pieces of burnt clay and, more intriguingly, a fragment of iron slag, a by-product of metalworking, which adds a small complication to any simple reading of the site. The finds were documented by Halpin in 2002 and Dunne in 2003.

Scattery Island is accessible by seasonal ferry from Kilrush, and the mound sits in the cluster of monuments near the island's distinctive roofless round tower. Because the mound is so low-lying, it reads more as a slight irregularity in the ground than any obvious earthwork, so knowing it is there, and knowing what to look for in the faint scatter of the landscape, is most of the work.