A small stream branches off from the Kings River to the west, running just 20 metres south of the fortification before rejoining the main river to the southeast. The bailey sits elevated above the island floor, which is prone to flooding; the ground around its base was once marshy but has since been reclaimed. While the position offers excellent views east and west along the valley floor, rising ground to the north and south limits visibility in those directions.

The site’s history stretches back to 1192-3, when Geoffrey FitzRoberts likely built the motte and bailey whilst founding the town of Kells. Early 13th-century documents refer to the ‘castelli’ at Kells, probably describing a timber castle that once stood atop the motte. The fortification later gained a bawn that follows the perimeter of the original bailey, possibly the ‘fortilagium’ mentioned in a 1621 inquisition. After the FitzRobert lordship ended around 1308-1312, the castle passed through various absentee landlords during the 14th century, including the le Poers, Berminghams and Prestons, before transferring to Thomas Butler, prior of Kilmainham, and his heirs in the 15th century, and eventually to the Viscounts Mountgarret in the 16th and 17th centuries.

Today, the ground level within the bailey slopes northwest and features an undulating landscape of low mounds and hollows. Whilst records suggest a masonry castle may have been constructed alongside the bawn, no visible traces remain at ground level within the fortification. The site represents nearly a millennium of Irish defensive architecture, from its origins as a Norman stronghold to its later adaptations, all strategically positioned to control this important river crossing in County Kilkenny.