A burnt mound, sometimes called a fulacht fiadh, is essentially the accumulated debris of repeated water-boiling using fire-heated stones. The stones crack and shatter with thermal shock, becoming useless for further heating, and so they pile up alongside charcoal into a distinctive mound. The one at Neigham measures roughly 12 metres north to south and at least 7 metres east to west, surviving as a truncated spread buried only about 0.25 to 0.3 metres below the sod.

The site came to light during archaeological monitoring carried out under licence in 2004, recorded by McLoughlin. What made the findings particularly interesting was not just the mound itself but three pits found in close proximity to it. Two lie about 1 to 1.5 metres to the west, one measuring 1.6 metres north to south and 0.5 metres deep, the other slightly smaller at 1.2 metres north to south and 0.4 metres deep, situated roughly 5 metres to the north of the first. A third pit, measuring 1.3 metres north to south and 0.7 metres east to west, sits about 2.8 metres to the north of the mound spread itself. All three contained charcoal and burnt stone, strongly suggesting they formed part of the same activity. Pits associated with burnt mounds are often interpreted as the troughs in which water was heated, with stones dropped in from a nearby fire. Crucially, the site sits approximately 30 metres north-west of a separate moated site, a type of enclosed medieval farmstead, raising the possibility that this small landscape was in use across more than one period of Irish history.