It looks, at first, like a rough stone wall, three metres high and nearly four metres wide, built from random rubble in the way of many old farm structures. But the lintelled recess cut into its face, and the long earthen ramp that rises behind it, tell a more particular story about how land was worked before synthetic fertilisers changed farming entirely.

A lime kiln was an industrial structure at the heart of agricultural life. Farmers would load limestone and fuel, usually coal or wood, into the funnel at the top, light a fire, and draw off the quicklime from the draw hole at the base, here the lintelled recess measuring roughly 1.8 metres tall, 1.6 metres wide, and 1.4 metres deep. The quicklime was then spread across fields to reduce soil acidity and improve crop yields. The kiln at Toornanaunagh follows this standard form: a ramp of approximately twelve metres runs up to the rear of the structure, allowing loaded carts or panniers to reach the funnel, which measures 1.8 metres in diameter at the top. The south-facing orientation would have made practical sense, offering some shelter from prevailing weather during the slow burn that could last several days.