A fulacht fia, the Irish term for a prehistoric cooking or heating site, typically consists of a trough dug into the ground and a surrounding mound of fire-cracked stones; the stones were heated in a fire and dropped into the water-filled trough to bring it to temperature, then discarded once spent. Over time, the rejected fragments accumulate into the distinctive horseshoe-shaped mound that archaeologists recognise across the Irish landscape in their thousands. What makes the Tulla example quietly remarkable is how well-preserved and precisely dated it turned out to be, and how it sat unsuspected beneath what had been wet pasture until a school building project brought it to light.

The site came to attention in January 2015 during monitoring of groundworks for the development of St Joseph's Secondary School. Excavation followed in February of that year, directed by Alison McQueen. Topsoil stripping revealed a large, irregular spread of burnt material measuring roughly 20 metres east to west and 12.5 metres north to south, shallow but dense with heat-shattered stone and charcoal. Natural springs at the perimeter of the spread would have supplied the water the site required. At the centre lay a well-defined rectangular trough, 3.25 metres long, 1.9 metres wide, and just under half a metre deep, cut directly into the natural subsoil. The local clay content was high enough to make the subsoil effectively waterproof without any additional lining. Five large stones arranged in a semi-circle at the base of the trough appeared to have been deliberately placed, possibly to allow someone to step down into it. Radiocarbon dating of two distinct layers within the mound produced dates of around 940 BC for the lower, earlier material and around 870 BC for the upper layer, suggesting the site was in active use for roughly eighty years during the Late Bronze Age. The wood recovered from the mound and trough deposits was dominated by alder and ash, both common in wet ground conditions of the kind the springs would have encouraged. A single intact tooth from a domestic animal was recovered from the upper fill. Two further burnt mounds had already been excavated some 45 and 100 metres to the south in 2014, indicating that this stretch of low-lying ground saw repeated use across a considerable period.