Five burnt mounds, or fulachtaí fia, were discovered in Coolnaleen Lower and Garryantanvally townlands.

Burnt mounds are the most common prehistoric site type in Ireland and mostly date to the Bronze Age (2500–500 BC). They consist of mounds of heat-shattered stone and charcoal-enriched soil, usually located in low-lying, marshy areas close to a stream or spring. Troughs (for heating water), as well as hearths, stakehole alignments and pits, are often found next to or beneath the mounds. They are generally thought to have been cooking places but may also have served other functions.

Multiple purposes are certainly indicated at Coolnaleen Lower 1. Joints of meat could have been cooked in the three wood-lined troughs uncovered here, while the discovery of a wood-and-stone bench, built into the side of a 4m wide pit, suggests the site may also have been used for communal bathing, or perhaps as a sauna.

A small number of stone artefacts, including a shale axehead, were also found at this site.