The field looks unremarkable today, its former earthworks long since smoothed away, and nothing in the landscape gives any indication that something deliberately shaped and considerable in scale lies quietly beneath it.

The enclosure came to light not through excavation but through a magnetometer survey carried out in 1981, ahead of construction work on the Cork to Dublin gas pipeline. Magnetometry is a non-invasive technique that detects variations in the magnetic properties of buried soils and features, allowing archaeologists to map what lies underground without lifting a sod. What the survey revealed was a deep U-shaped ditch, between two and four metres wide and up to nearly two metres deep, running roughly forty metres north of a nearby castle and approximately twenty metres to its east and west. Taken together, the measurements suggest the ditch formed a D-shaped enclosure around that castle, recorded over a length of forty-seven metres on the eastern side and fifty metres on the western. The relationship between the ditch and the castle it appears to surround is logical enough, since enclosures of this kind were commonly used to define and defend a castle's immediate precinct, but the absence of any finds from the ditch means its precise date of use remains unknown.