The castle’s location appears on the first edition Ordnance Survey 6-inch map, carefully marked as ‘Site of Clonmullen Castle’, preserving the memory of what was once a significant local fortification. Like many Irish castles, particularly those built during the medieval period, Clonmullen has vanished entirely from the landscape, leaving only historical records and map references to indicate its former presence.

The complete absence of any above-ground traces suggests the castle may have been systematically dismantled, with its stones likely repurposed for local building projects; a common fate for many abandoned fortifications across Ireland. The strategic positioning on elevated ground near a water source follows the typical pattern of Anglo-Norman castle placement in Ireland, where defensive advantages and access to fresh water were paramount considerations. Archaeological investigation might reveal foundation trenches, post holes, or other subsurface features that could help determine the castle’s original footprint and construction methods.

This information comes from the Archaeological Inventory of County Carlow, first published by the Stationery Office in Dublin in 1993, with updates incorporated from ongoing research. The inventory represents one of the most comprehensive surveys of Carlow’s archaeological heritage, documenting sites ranging from prehistoric monuments to post-medieval structures, ensuring that even vanished castles like Clonmullen remain part of the county’s recorded history.