An embanked enclosure is broadly what it sounds like: a roughly circular area defined by an earthen bank, used in prehistoric and early medieval Ireland for purposes that varied from settlement and livestock management to ceremonial activity, depending on the site. At Knockbrandon, the enclosure once measured somewhere between forty and forty-five metres in external diameter, making it a significant presence in this quiet corner of the county.

The site was recorded clearly on the Ordnance Survey six-inch map of 1839, where the full circuit of the enclosure was visible. By the time the 1940 edition of the same map was produced, only a faint fragment of the bank survived in the northern section, suggesting that the intervening century had taken a considerable toll through agriculture or land improvement. What remains today is a slightly raised grassy area of about thirty metres across and no more than thirty centimetres in height, the merest suggestion of what stood before. The enclosure sits on a shelf of land with hilltops rising to the north-west at roughly three hundred and seventy metres away, and to the south at around nine hundred metres, while the valley floor lies about a hundred and fifty metres to the south, opening eastward. It is the kind of positioning that recurs at Irish enclosure sites, where elevated ground with a commanding outlook seems to have been a deliberate choice.