This impressive earthwork stands as a steep-sided, oval mound reaching between 4.5 and 6 metres in height, with a base measuring approximately 24 metres from northeast to southwest and 16 metres from northwest to southeast. The Inny River flows about 450 metres to the south, placing this fortification in a strategic position overlooking the river valley.

The motte is encircled by fragmentary traces of what was once a wide, shallow fosse; a defensive ditch that would have provided additional protection to the castle’s occupants. Unfortunately, later quarrying has left its mark on the structure, creating a large cavity on the summit that measures 16.5 metres by 12.5 metres, as well as damage to the north face of the mound. This quarrying activity, whilst destructive to the archaeological integrity of the site, inadvertently reveals the construction methods used in building these Norman fortifications, showing the layers of earth and stone that were piled up to create the artificial hill.

Adjacent to the east of the motte, traces of additional castle structures survive, though these remains are currently unclassified pending further archaeological investigation. Together, these features represent a typical Norman defensive complex at Castlecore, likely dating from the late 12th or early 13th century when Anglo-Norman lords were establishing their control over the Irish midlands. The site was compiled for archaeological records by Caimin O’Brien and uploaded to the national database on 15 March 2012, ensuring its preservation in Ireland’s archaeological inventory.