Their roots follow the course of a fosse, the shallow defensive ditch that once ran around the outside of a rath, the Irish term for a ringfort, typically a circular earthen enclosure built during the early medieval period as a farmstead or place of shelter. The iris plants have colonised the slight depression where the fosse runs, two metres wide and only about fifteen centimetres deep, tracing an arc that is now more botanical than archaeological.

The 1842 Ordnance Survey six-inch map recorded the structure as a hachured arc running from south-southeast to west, sitting in the north-northeast corner of a field. What survives today is a partial arc from southeast to north-northeast, with a minimum diameter of around twenty metres on the north-south axis. The bank itself rises only about fifteen centimetres above the surrounding ground, barely a rumple in the pasture. Two sections of the enclosure have been effectively absorbed by later field boundaries: the northwest side has been swallowed by a wide, flat-topped earthen field boundary measuring four and a half metres across, while the east-northeast side has disappeared entirely beneath another field margin, leaving no visible surface trace at all. The rath has been quietly dismembered by the ordinary business of farming over the centuries, its original circuit now parcelled out between field divisions that have no memory of what they replaced.