This imposing motte, standing roughly seven metres high with a flat summit spanning 22 metres across, represents the remains of the castle of Athroynny, which met its demise at the hands of Murtough O’Brien in 1207. The structure sits on slightly elevated ground near a crossing of the Glorian River, where the medieval New Town of Athronny once flourished on the eastern bank, likely just south of today’s village. A water-filled fosse, approximately four metres wide and partially lined with limestone walling, still encircles much of the mound, though the northern and northwestern sections have been lost to time.

Local tradition adds an intriguing layer to the site’s story, with residents long referring to it as ‘The King’s Grave’, suggesting the motte may have been constructed atop an earlier burial mound. This theory gains some weight from historical records, including a marginal note in an old Irish manuscript held at Trinity College Dublin, which mentions that Conall, son of David O’More, King of Leix, rebuilt Dunamase castle after capturing it from the English and also constructed a castle at what appears to be Ballyroan, though the Irish rendering is somewhat unclear. The site’s strategic importance is evident from its position controlling the river crossing, and traces of the medieval settlement can still be discerned in the raised, stone-scattered areas to the south and west of the mound.

Today, this monument enjoys protection under a preservation order dating from 1952, recognising its significance as one of Ireland’s Anglo-Norman earthwork castles. The motte’s distinctive profile, with what historical accounts describe as a terraced passage winding around its sides to the summit plateau, offers visitors a tangible connection to the turbulent medieval period when Gaelic Irish lords and Anglo-Norman settlers vied for control of the Irish midlands. Though trees now grow where a timber castle likely once stood, the earthwork remains an impressive testament to the region’s complex medieval heritage.