At its centre, the cartographers noted something unexpected: a limekiln, the kind of small stone furnace once used to burn limestone into quicklime for fertilising fields. That a working agricultural structure should sit at the heart of what had been an early medieval ringfort says something about how thoroughly the past can be absorbed into the working landscape.

A ringfort, or rath, was typically a circular enclosure defined by one or more earthen banks and ditches, used as a farmstead and defensive residence during the early medieval period, roughly the fifth to twelfth centuries. Thousands survive across Ireland, though many more have been lost to exactly the kind of agricultural activity recorded here. At Pollnamal, the site lies south of a related earthwork and is associated with a cashel-type structure, suggesting this corner of Galway once held a modest but meaningful cluster of early settlement. By the time the first Ordnance Survey teams moved through Connacht in the nineteenth century, the ringfort itself was already being put to agricultural use, with the limekiln occupying its interior. Today, the land is under tillage and no surface trace of the enclosure survives at all.