The site appears as a rectangular, grass-covered mound measuring roughly 25 metres north to south and 17 metres east to west at its base, rising to a flattened top that’s slightly smaller in dimension. Years of quarrying, particularly on the eastern side, have left the mound scarred with irregular scarps ranging from less than a metre to nearly two metres in height.

The earthwork tells a story of a once-significant stronghold that played a role in the turbulent politics of 16th-century Connacht. Historical records reveal that Hugh Mc Tirrelagh Roe, Tanaiste of O’Conor Roe, held the castle of Cloniberne in 1585, but by 1596 he had lost control of it to Irish rebels during the upheavals of that period. The defensive nature of the site is still evident in its surrounding fosse or quarry ditch, which varies in depth from a mere 20 centimetres in places to over a metre at its deepest point. Beyond this, an irregular earthen bank extends around much of the perimeter, creating a total enclosed area of approximately 38 metres by 36 metres.

Despite its local designation as a castle and the discovery of a cannonball on the site (unfortunately now lost), no dressed stone or masonry walls remain visible anywhere within the enclosure. The Ordnance Survey mapped it as a circular embanked enclosure in 1837, with an external diameter of about 40 metres, and today it forms part of a wider archaeological landscape that includes an adjacent field system and settlement cluster immediately to the west. The absence of stone structures suggests that any buildings that once stood here may have been of timber construction, or that stone was comprehensively robbed out over the centuries for use elsewhere.