A spread of heat-shattered stones and charcoal-enriched soil, roughly twelve metres across, sits close to a small stream, invisible to anyone walking past today. There is nothing to see above ground, and that near-total absence is itself part of what makes the site worth understanding.

What was uncovered here is known as a burnt mound, a type of prehistoric site found in considerable numbers across Ireland, Britain, and Scandinavia. The working theory is that these accumulations of fire-cracked stone represent the debris of a cooking method in which stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil, a process repeated until the stones cracked and were discarded in a heap. Over time, these heaps built up into the low, horseshoe-shaped mounds that survive elsewhere as visible features in the landscape. At Ballygibbon, a two-and-a-half-metre-wide test trench excavated in 2006 exposed the spread, revealing the characteristic mix of shattered stone and darkened soil. When the site was visited the following year, the trench had been backfilled and the spread had returned to invisibility. A second possible burnt mound was identified approximately twenty metres to the west, suggesting this stretch of ground near the stream was used repeatedly, or by more than one group, over time.