At Poulacapple in County Tipperary, a roughly circular prehistoric enclosure exists in the record almost entirely because of a single aerial photograph, taken on the 16th of April 1974. On that image, the outline of the enclosure shows up as a cropmark, the kind of ghostly variation in plant growth that betrays buried features beneath the surface. On the ground, among dense rushes on a gently north-west-facing slope within commercial forestry, there is nothing to see.

Cropmarks form when buried walls, ditches, or pits affect how overlying soil retains moisture and nutrients. Crops or grasses above a buried ditch tend to grow taller and greener; those above a buried wall tend to be stunted. From the air, these differences can trace out the plan of a structure that has otherwise entirely vanished. The photograph that caught this particular enclosure was taken as part of a geological survey series, not an archaeological one, which makes the discovery a quiet accident of record-keeping. What the enclosure actually was, how old it is, and who built it remain unknown from the available evidence. What can be said is that roughly 31 metres to the north-west lies a fulacht fiadh, a type of site found widely across Ireland, typically interpreted as a burnt mound associated with outdoor cooking or heating water, usually Bronze Age in date. The proximity of the two features may be coincidental, or it may reflect a broader pattern of activity in this small corner of Tipperary, but the evidence does not extend far enough to say more.