These structures, built to burn limestone at high temperatures and produce quicklime, were essential to farming communities for centuries. The resulting lime was spread on acidic soils to improve fertility, used in mortar for building, and applied as a whitewash on cottage walls. That such a kiln exists on an island setting makes it a small but pointed reminder that even remote or seasonally inhabited places were once bound up in the ordinary business of working the land.

Lime kilns of this kind were typically built close to a supply of both limestone and fuel, often positioned near a coastal slope or hillside to allow easy loading from above. They appear across Ireland from at least the medieval period, though many surviving examples date from the eighteenth and nineteenth centuries, when agricultural improvement movements encouraged landowners and tenants alike to invest in soil management. The presence of one on An Inse Mhór suggests the island supported a degree of settled or working life substantial enough to justify the effort of constructing and operating it, no small undertaking in an island context where materials and labour had to be brought across water.