It is easy to walk past, and most people do. But a cross-section exposed in the stream bank tells a more interesting story: roughly thirty centimetres below the sod, a layer of burnt stone sitting in charcoal-rich soil stretches for around five metres, and beneath that lies a course of flat-laid stones, each one no bigger than a dinner plate. This is a burnt mound, one of the most common and least explained monument types in the Irish countryside.

Burnt mounds are the accumulated debris of a cooking or industrial process that was repeated, probably over generations, during the Bronze Age. The basic method involved heating stones in a fire until they were hot enough to boil water when dropped into a trough or pit. The stones, fractured and blackened by the thermal shock, were then raked out and discarded, building up over time into the characteristic low, spread mounds that survive in their thousands across Ireland. What exactly was being cooked, or whether the hot water served some other purpose entirely, remains genuinely open. The Shanvally mound follows the classic profile: a curved face on the landward side and a straight western edge where the stream runs, since proximity to moving water was essential to the whole operation. The mound measures roughly eight to ten metres north to south and six to seven metres east to west, modest in scale but well-preserved in section. A forestry trench clips its eastern edge, and the plantation of conifers begins just beyond that boundary, leaving the mound itself unplanted and still legible in the landscape.