A large enclosure, roughly 40 metres in diameter, was never excavated and has left no obvious surface trace, yet geophysical survey has revealed enough to suggest that whoever built it went to considerable effort, raising a bank inside a ditch some two metres wide and enclosing within it a collection of pit-like features and what may be the outline of a structure.

The enclosure came to light through a geophysical survey carried out under Licence no. 12R010 by the Discovery Programme, as part of its 'Late Iron Age and "Roman" Ireland' project, a research initiative examining the period roughly spanning the early centuries AD when Roman influence was being felt across Britain and, to a debated degree, along the Irish coast. The survey results, published by Dowling in 2013, placed the enclosure approximately 200 metres south-west of a ring ditch cemetery, a type of monument consisting of circular ditched features that typically mark prehistoric burial activity. The proximity of the two sites raises questions that remain unanswered: whether the enclosure and the cemetery were contemporary, and what the relationship between them might have been. A circular enclosure of this kind, defined by an internal bank and external ditch, is broadly comparable to a class of enclosed settlement or ceremonial site known from the Irish Iron Age, though without excavation the function here is genuinely unknown.

The site carries the reference number DU005-175002- in the national monuments record, which is the most reliable way to locate it on the Sites and Monuments Record map maintained by the National Monuments Service. The enclosure is not signposted and sits on private land, so the survey data and associated records held by the Discovery Programme are likely to be the most accessible route to understanding what is here. The Popeshall hill area of Thomastown, in the Balrothery East barony, is agricultural land, and the enclosure itself is invisible on the surface. It is the kind of place that exists more vividly in archive than in landscape, its shape preserved in the readings of survey equipment rather than in stone or earthwork.