Walk across it and you might notice faint, irregular undulations underfoot, but they form no obvious pattern and offer no obvious explanation. It is only when viewed from the air that the land gives itself away, resolving into a network of intersecting lines and roughly rectilinear shapes that together outline a field system covering approximately 2.6 hectares, roughly triangular in plan, and entirely invisible on any Ordnance Survey historical map.

The site at Kilderry sits in generally level ground in County Limerick, close to the townland boundary with Kildonnell to the west. It was first identified through aerial photographs taken as part of the Bruff Survey, a programme of aerial reconnaissance that documented archaeological features across this part of the country. The photographs, catalogued as Bruff 113: AP4/3648, showed intersecting linear cropmarks, the kind that form when buried earthworks or disturbed soil affect how grass and crops grow above them, producing visible differences in colour and height that only become legible from altitude. The Archaeological Survey of Ireland recorded the monument formally in 2000, noting at ground level only those vague undulations that resist interpretation. Later aerial imagery confirmed what the Bruff photographs had suggested: Digital Globe orthophotos taken between 2011 and 2013, and Google Earth images from February 2018, both show the cropmark field pattern clearly. There are also faint traces of further linear marks to the southwest, which may indicate the system extends beyond the area currently recorded. A separate enclosure monument sits roughly 200 metres to the south-southwest.

Because this monument is defined entirely by cropmarks, there is genuinely little to see at ground level, and the site sits on private farmland. The value here is as much conceptual as visual: knowing that an organised field system, old enough to have been erased from all later cartographic records, lies just beneath an ordinary-looking pasture changes the way the landscape reads. Cropmarks show up best in dry summers, when stressed vegetation above buried features turns yellow or brown ahead of surrounding growth. Anyone with an interest in landscape archaeology and access to the aerial photographs held via the Bruff Survey, or through Google Earth at the coordinates for Kilderry townland, can trace the outlines for themselves without setting foot on the land.