A fulacht fia, to give the type its Irish name, is a Bronze Age burnt mound, typically formed beside a water source where stones were heated in fire and then dropped into a water-filled trough to bring it to the boil. The process left behind distinctive horseshoe-shaped mounds of cracked and blackened stone, and Ireland has thousands of them, making them one of the most common field monuments in the country. What makes the Lisdangan example quietly unusual is the sheer concentration of activity in one small area: not one such site but at least four, clustered within close proximity of one another.

Two of the mounds, recorded individually, appeared on an Ordnance Survey six-inch map made in 1937, confirming they were visible features in the landscape within living memory. All three of the originally documented mounds have since been levelled, most likely through agricultural activity over the intervening decades, and what remains is a large spread of burnt material that blurs the boundaries between them, incorporating scorched debris from each. A fourth fulacht fiadh lies immediately to the east, adding further weight to the sense that this particular stretch of ground beside a stream, roughly forty metres to the west, was returned to repeatedly across what may have been a considerable span of prehistoric time.