That small detour in the road's alignment is one of the clearest signs that something older is being quietly respected, or at least worked around, by the landscape. The monument in question is a bivallate enclosure, meaning one defined by two concentric banks with a ditch, or fosse, between them. Oval in shape and roughly 50 metres across its longer axis, it sits in farmland, worn down but not entirely gone.

In 1950, during Land Project improvement works, labourers began levelling the inner bank and uncovered human remains belonging to approximately fourteen individuals, buried around 0.6 metres below the surface along the eastern side. Both the inner and outer banks were substantially reduced during those works, though the enclosure was not completely obliterated. The discovery was recorded in National Museum correspondence dated 12 August 1950, but the bones raise questions that were never fully answered. Enclosures of this type are often associated with early medieval settlement in Ireland, and burials within or beside their banks are not unknown, though the relationship between the two here remains unclear. A further enclosure lies roughly 100 metres to the northwest, suggesting this corner of Kilkenny was once more intensively occupied than its present quiet appearance suggests. Writing in 1883, a local historian named Holahan noted that Mountgale was formerly called Bouncestown, and recorded a local tradition identifying a circular mound near the road as the site of a castle belonging to Sir Tobias Butler. It is possible, though not certain, that this tradition referred to the same earthwork.