This rectangular earthwork measures approximately 27.6 metres east to west and 23.8 metres north to south, with its boundaries marked by a prominent scarp that rises 1.3 metres above the surrounding landscape. The site’s defensive character is immediately apparent from its well-preserved fosse, or defensive ditch, which runs around the perimeter with a width of 4 metres and varying depths between 0.3 and 0.6 metres. On the western side, this ancient ditch has been rather pragmatically incorporated into a modern drainage system that runs north to south.

The site’s original builders didn’t stop at a single line of defence; remnants of an outer bank, roughly 5 metres wide, can still be traced along the northern and southern edges, sitting at the outer lip of the fosse. The eastern side features the site’s main entrance, where a 4.6-metre-wide causeway crosses the defensive ditch, providing access from a small hillock that overlooks the entire complex. Just inside this entrance, archaeologists have noted a shallow hollow measuring about 4 metres across and 0.3 metres deep, though its original purpose remains unclear.

This type of moated site represents a fascinating chapter in medieval Irish history, typically dating from the 13th to 14th centuries when Anglo-Norman settlers and Gaelicised families built these defended homesteads across the countryside. The Altanelvick example, documented by Patrick F. O’Donovan in 2011, shows all the classic features of these sites; the raised platform would have supported timber or stone buildings, whilst the surrounding water-filled ditch provided both defence and drainage in what remains boggy ground to this day.