Known locally as O’Kelly’s Castle, this rectangular grass-covered platform measures roughly 12.7 metres east to west and 8.4 metres north to south at its top, expanding to 16 metres by 13 metres at its base. The structure is defined by earthen scarps that range from 30 to 50 centimetres in height, with traces of the original stone walls still detectable underfoot; approximately 1.3 metres wide on the western side and 1 metre wide on the eastern side.

The site’s history is intertwined with the fortunes of local landowning families. In 1641, Richard Dillon owned the Castle Quarter of Corenegee, also known as Lisnaguill, which comprised 154 acres. Dillon, likely connected to the influential Dillons of Lough Glynn, controlled over 600 acres in Cam parish and managed to retain most of his holdings through the turbulent period following the Cromwellian conquest, still possessing the land in 1662. Interestingly, the area appears on Strafford’s map from around 1636, where Lough Croan is labelled as Loughanabrag, providing a valuable glimpse into how place names have evolved over the centuries.

Though the castle itself now exists only as earthworks, several intriguing medieval artefacts associated with the site have survived. A limestone head measuring 17 centimetres in height, believed locally to have originated from this monument, is now housed in the National Museum of Ireland. Additionally, architectural fragments including the heads of two ogee-headed windows have been incorporated into farm outbuildings approximately 330 metres northeast of the castle site, serving as tangible reminders of the structure’s former grandeur and the continuous reuse of medieval stonework in the Irish countryside.