The site near Grangestown presents the outward shape of a ringfort, the circular or sub-circular enclosures that dot the Irish landscape in their thousands, typically consisting of a raised interior platform enclosed by an earthen bank and a fosse, which is the shallow ditch dug to provide material for the bank. Here, the bank is poorly preserved and the fosse no more than slight. The interior, roughly 40 metres north to south and 37 metres east to west, has been heavily disturbed.

The disturbance has a documented cause. The Ordnance Survey six-inch map of 1837 marks a gravel pit at this precise location but records no antiquity whatsoever, suggesting that at that point nobody regarded the feature as a monument worth noting. By the time the revised edition appeared in 1875, however, the earthwork is shown as a recognisable circular feature, with the gravel pit occupying the north-east quadrant of its interior and an access path cutting in from the north-east. The Yellow River runs roughly 130 metres to the east, and a second ringfort sits about 140 metres to the south-east. That proximity to a confirmed monument is one reason the site is taken seriously, but the timeline revealed by the two maps creates a real puzzle. The digging of gravel may have inadvertently sculpted something that looks, at a certain distance, like a prehistoric enclosure, rather than exposed one.