This fortification at Shanakyle represents a type of early Norman stronghold that preceded the stone castles more commonly associated with medieval Ireland. The main defensive ring measures 38 metres east to west and 23 metres north to south, protected by an impressive combination of earthworks that would have made any assault a formidable challenge.

The defences vary dramatically around the oval enclosure, adapting cleverly to the natural topography. Along the western and northwestern sides, a substantial earthen bank rises up to 1.25 metres high externally, with its base spreading nearly 13 metres wide. This bank is accompanied by a deep, wide fosse, or defensive ditch, cut 1.85 metres into the earth. The northeastern quadrant takes advantage of a natural steep scarp that drops 3.4 metres, whilst the eastern and southern approaches are guarded by a lower scarp and shallower ditch system. Access to the interior was carefully controlled through a single entrance at the north, reached via a ramped causeway that curves around the northwestern bank’s contour.

Evidence suggests this wasn’t a standalone fortification; traces of a possible outer bank to the west may indicate a bailey area extending another 27 metres, which would have provided additional defensive space for buildings and livestock. The site’s strategic positioning made good use of natural water sources, with channels to the southwest and a narrow channel, possibly artificially enhanced, located to the east-southeast. Today, a modern field boundary cuts across the monument’s interior, but the earthworks remain remarkably well-preserved, offering visitors a chance to walk the same defensive circuit that medieval defenders once patrolled. Another enclosure lies approximately 250 metres to the northeast, suggesting this area held considerable strategic importance in medieval times.