The oval enclosure at Lisduff measures roughly 32 metres along its longer axis and 26 metres across, but the earthen bank that once defined it has been so thoroughly reduced by agricultural improvement that in most places it rises less than twenty centimetres above the surrounding pasture. A ringfort, to explain the term briefly, is a circular or oval enclosure defined by one or more banks and ditches, built across Ireland roughly between the early medieval period and the early centuries of the second millennium, typically as a defended farmstead. Here, the bank survives in any meaningful form only along the western to north-north-eastern arc; the north-north-eastern to eastern side has been levelled out almost entirely. A curvilinear field boundary running from the east-south-east to the south-west appears to have absorbed and incorporated what remained of the bank on that side, which accounts for its slightly more pronounced profile in that sector. A gap of about nine metres on the west to west-south-west side is consistent with an original entrance.

The fort is named on all Ordnance Survey historic mapping as Knockaclocaun Fort, which at least confirms that it was recognisable as a monument through the nineteenth century even if it was already in decline. What makes the site quietly strange today is its relationship to the surrounding landscape. It sits on gently undulating low ground, overlooked by higher terrain to the west and north-east, and it overlooks another ringfort just twenty-five metres to the south-east. Two ringforts in such close proximity suggests deliberate pairing or at least contemporaneous use of the same small area, though what that relationship meant in practical or social terms is not recorded. The low-lying setting, open to improved pasture on all sides, means the monument has had little protection from centuries of farming activity, and what remains is more a faint signature in the ground than any upstanding earthwork.