At roughly 200 metres from north to south and 100 metres from east to west, this is no small feature; it would have enclosed a considerable area, roughly comparable in scale to several football pitches laid end to end. Yet most of it has vanished, and what remains is so thoroughly woven into the working landscape that it takes a deliberate eye to recognise it as something older and more purposeful.

The enclosure belongs to a category of monument common enough in Irish archaeology but still poorly understood: a large earthen enclosure defined by a bank and an external fosse, which is simply a shallow ditch dug on the outer side of the bank, intended to heighten the boundary and perhaps to mark territory or contain livestock. The surviving eastern section retains a bank roughly two to two and a half metres wide and just over a metre high, with a fosse outside it measuring around one and a half metres wide and half a metre deep. The interior, where it can be assessed, is dry and level despite the waterlogged character of the surrounding terrain. The enclosure was already recorded on the Ordnance Survey six-inch map of 1838, which means it was a legible feature in the landscape at that point, though its original date of construction remains uncertain. Liam Price, writing in 1945, noted the site, and it is from that reference that the surviving description largely derives.