At Ballylarkin in County Kilkenny, what survives of this early medieval earthwork is roughly D-shaped rather than the circular form you might expect, and the reason for that truncation is written into the landscape itself.

A ringfort, or rath, was typically a circular enclosure defined by an earthen bank and a surrounding ditch, used as a farmstead during the early medieval period in Ireland. This one sits within the grounds of Woodview House, and already by the time the revised Ordnance Survey six-inch map was produced in 1900, only the western portion of the monument was being recorded. The eastern half, which lay on the far side of a townland boundary running northwest to southeast, appears to have been levelled at some point, leaving behind a D-shaped remnant with internal dimensions of roughly 22 metres northwest to southeast and 12 metres east to west. The surviving section retains a slight enclosing bank and an external fosse, a shallow ditch that would once have reinforced the boundary of the whole enclosure, running from the northwest around through west and south to the southeast.