The circular enclosure at Reacaslagh in County Kerry was, by the time anyone properly examined it in 1987, already a puzzle: three concentric earthen banks, a wide and well-defined fosse (a defensive or boundary ditch) between the outer two, and a central area only about sixteen metres across. That interior is conspicuously small for a structure defended by three banks, slight as they were. The surveyors considered whether it might be a ringbarrow, a low mounded burial monument of the Bronze Age, but there was no central rise to suggest a burial mound beneath. So it sat awkwardly between categories, eventually recorded simply as a circular enclosure, a classification that admitted more uncertainty than it resolved.

When a survey team from the Castleisland District Archaeological Survey examined the site in 1987, they found the monument largely smothered in a layer of springy peat, which both preserved and obscured it. The overall diameter reached roughly thirty-nine metres, with the banks standing only about twenty centimetres high and spread wide, suggesting considerable age and weathering. Five years later, on 28 March 1992, Patricia O'Hare returned to find the enclosure gone. Deep ploughing had levelled it entirely, cutting down to a depth of between 0.8 and 0.9 metres. What remained told its own story: the bank lines showed as streaks of yellowish soil mixed with small stone, while the ploughed interior, stripped of that stony matrix, was covered in deep black peat. The contrast between the two soils made the ghost of the monument briefly legible, even as the ploughing had erased it. By the time satellite imagery captured the area between 2011 and 2013, only a cropmark remained, a faint trace visible from above of something that had not been fully understood when it still stood above ground.