It is a corn-drying kiln, a type of structure once common across rural Ireland but now largely forgotten beneath grass and general indifference. Unlike a grain store or a mill, a corn-drying kiln had a single, unglamorous purpose: to dry harvested grain before milling or storage, a necessary step in a climate where moisture was a constant enemy of the harvest.

The kiln at Gleann Daimh is modest in scale but complete enough in its surviving form to be legible. The drying chamber is circular and uncovered, measuring just 1.3 metres in diameter and standing only 0.45 metres high, its walls faced with roughly coursed sandstone blocks. Leading into it from the north-east is a stone-lined flue, the tunnel through which heat from a fire would have been drawn up into the chamber above. The flue measures 1.4 metres in length and 0.65 metres wide, and one of its original lintels, the flat stones laid across the top to cap the passage, remains in position. The whole arrangement is small enough to crouch beside and examine closely, its construction straightforward but deliberate. The kiln sits on the northern edge of an area of natural rock outcropping, roughly 300 metres north of a ringfort, suggesting a cluster of agricultural and settlement activity in this part of the landscape at some point in the past, though the precise period of the kiln's use is not recorded.