During groundworks along the route, three corn-drying kilns came to light at Coolbeg, buried beneath the surface and preserved well enough to reveal that they had been used repeatedly over multiple periods of time.

Archaeologist Goorik Dehaene excavated the site, recorded under reference E3256, uncovering kilns built in the figure-of-eight shape that was common to this type of structure across early medieval and later Ireland. A corn-drying kiln, sometimes called a corn-drier, was a low stone or clay construction used to dry harvested grain before milling or storage, a necessary step in the damp Irish climate where grain left undried would quickly spoil or fail to grind properly. The figure-of-eight design allowed a fire to be drawn through the lower chamber and the heat to circulate upward into the drying bowl above. The presence of many phases of use in these kilns suggests the site was returned to over a considerable span of time, implying it served an agricultural community that found the location reliable and practical across generations. Clustered around the kilns were a series of pits, each with a circular outline and a flat base, cut into the ground at regular intervals. Dehaene interpreted these as storage pits associated with the kiln activity, likely used to hold grain before or after drying.