Burnt mounds, known in Irish archaeology as fulachtaí fia, are among the most common prehistoric field monuments in Ireland, yet they remain quietly mysterious. The leading theory is that they were used for cooking, possibly by heating stones in a fire and dropping them into water-filled troughs to bring the water to a boil, though other uses, including bathing, brewing, or textile processing, have also been proposed. What made the one at Knockadoon visible at all was sheer accident.

During archaeological monitoring of the Lough Mask Regional Water Supply Scheme between 2001 and 2002, the trench being cut for the pipeline exposed the mound in cross-section. That slice through the ground revealed a layer of burnt stone and charcoal roughly 0.3 metres thick, sandwiched between overlying topsoil and peat above, and a bed of marl, a calcium-rich sediment common in areas of former lake margins, below. The bulk of the mound continued southward beyond the pipeline corridor and remained untouched. Rather than disturb it further, engineers diverted the pipe to the north, and the archaeological deposits were left intact beneath the pasture. A charcoal sample taken from the layer was sent for radiocarbon dating and returned a Late Bronze Age date of 2850 plus or minus 45 BP, placing the activity at the site somewhere between 1130 and 890 BC. Three thousand years ago, someone was lighting fires in this same patch of flat ground beside what is now one of the largest freshwater lakes in Ireland.