This ancient cooking site, dating from 1109 to 897 BC, was discovered during excavations ahead of a proposed dam development. The site consists of a horseshoe-shaped mound of heat-shattered sandstone measuring 15 metres long and 13 metres wide, which enclosed a sophisticated timber-lined trough on its northwestern side.

The rectangular trough, measuring 1.6 metres by 1.1 metres and cut through peat into the subsoil below, reveals fascinating construction techniques from nearly 3,000 years ago. Bronze Age builders lined the pit with split alder planks and roundwood lengths, carefully wedged into place with corner pegs; nine planks formed the base whilst the sides stood three planks high. The trough contained remnants of moss and angular fragments of heat-shattered sandstone mixed with charcoal-rich peaty soil, with charcoal analysis revealing the use of oak, alder, hazel and hawthorn or mountain ash wood. Several shallow pits found 3 to 4 metres west of the main structure appeared to be associated with the fulacht fia, including a kidney-shaped pit that may have served as a secondary trough and yielded a single retouched flint blade.

The Croaghonagh site sits within a rich archaeological landscape spanning thousands of years. Immediately to the southwest lies a Neolithic cairn, whilst 25 metres away archaeologists discovered an Early Bronze Age wedge tomb. Additional Bronze Age features dot the surrounding area, including a pit 30 metres to the southeast and a burnt spread 60 metres away, both dated to the Middle Bronze Age. This concentration of prehistoric monuments suggests Lough Mourne’s shores held special significance for ancient communities over millennia, serving as a focal point for both ritual activities and daily food preparation.