No earthwork, no stone, no depression in the ground gives the site away. Yet beneath that ordinary agricultural surface, excavators in 1986 uncovered the remains of a corn-drying kiln, a structure that had once been central to the rural economy of the Irish countryside, used to dry harvested grain before milling or storage, typically by channelling heat through a flue into a drying chamber above.

What the 1986 excavation revealed was a keyhole-shaped structure, a form common to Irish corn-drying kilns, measuring up to 6.60 metres in length and 1.30 metres in width. The keyhole shape reflects the kiln's function: the long, narrow flue, called a draught or drafting flue, drew heat from a fire-bowl at one end into the circular drying chamber at the other. At Ballynaraha, the fire-bowl was clearly defined, and rough pebble paving survived at the entrance area of the flue. Most compellingly, charred cereal grain was recovered from the fill of the circular drying chamber, direct physical evidence of the kiln's last use, or perhaps of the event that ended it. O'Donnell, reporting in 1987, noted that no other features or finds were associated with the structure, and a full account of the excavation was later published by Gowen in 1988. The kiln was already partly destroyed when it was found, which is typical of structures that have lain under cultivated ground for centuries, each ploughing season shaving a little more away.