A cashel is a stone-walled enclosure, typically of early medieval origin in Ireland, though the term can apply to enclosures of varying periods. What makes this particular building quietly arresting is the combination of its modest scale and its setting: a roofless stone outline measuring roughly four metres north to south and just over three metres east to west, with a gap nearly two and a half metres wide at the northern end of the east wall, most likely the original entrance.

The structure does not stand alone. A second rectangular building lies to the northwest, also within the cashel interior, and the whole complex sits inside what has been recorded as an extensive field system, suggesting that the landscape around Ballybaun was once organised and worked in some deliberate, sustained way. The cashel itself would have functioned as a protected enclosure, possibly for livestock, for a farmstead, or for some combination of both. Having two separate buildings within a single cashel is not unusual in the Irish archaeological record, though the relationship between them, whether they were contemporary or separated by generations, remains an open question. The absence of a confirmed date is itself telling; without excavation or datable material, these walls offer no easy answers.