A field system, once stretching roughly 280 metres north to south and 200 metres east to west, has been entirely erased from the ground. The banks that once divided the land into several irregular fields are gone; the field in which they lay has been cleared and subdivided, and no visible surface trace survives. What was there is known almost entirely because two aircraft happened to pass over at the right moment.

The system came to light through aerial reconnaissance carried out in 1968 and again in 1987. From above, the earthworks were legible as a series of banks forming irregular enclosures around a ringfort and an adjoining enclosure. A ringfort, to be clear about the term, is a circular enclosed settlement of the early medieval period, typically bounded by an earthen bank and ditch, and they are among the most common archaeological monument types in Ireland. The fact that a field system wrapped around this one at Kilcahill suggests organised agricultural activity associated with whoever occupied the fort, though the precise dating of the fields themselves is not recorded. The two aerial surveys, separated by nearly two decades, together fixed the extent of the system before modern land improvement work removed it altogether.

There is nothing to see at Kilcahill today. The landscape has moved on, and the site is worth knowing about not for any surviving feature but for what its disappearance illustrates: that the archaeological record of rural Ireland is still being quietly dismantled, field by field, and that aerial photography has sometimes been the only thing standing between a monument and total obscurity.