Lime kilns were stone-built furnaces used to burn limestone at high temperatures, producing quicklime that farmers spread across acidic soils to improve fertility. For centuries they were a practical necessity, and their remains are scattered across Ireland in varying states of survival, often mistaken for field walls or natural outcrops.

The presence of one on An Inse Mhór points to a history of agricultural effort on what would have been a demanding environment to farm. Island communities along the Cork coast worked hard to make marginal land productive, and access to lime, whether from local stone or brought across by boat, was central to that effort. The kiln itself represents a period when islanders were actively managing their soil rather than simply enduring it, a detail that tends to get lost when attention turns to more dramatic monuments.