Not from the ground, not on any modern satellite image, and not on any of the Ordnance Survey's historic maps. The only record of its existence comes from a single aerial photograph taken in 1986, when the right combination of dry conditions and a growing crop briefly revealed a circular shadow in the earth, the ghost of something buried and long compressed beneath wet, poorly drained pasture.

This class of monument, a ring barrow, is a circular funerary earthwork typically consisting of a low central mound surrounded by a ditch and outer bank. They belong broadly to the Bronze Age, though some examples span into the Iron Age, and they appear across Ireland in considerable numbers, often in loose groupings. The Kilduff example sits within exactly such a cluster: two further ring barrows are recorded within 60 metres, one to the west and one to the north. The field itself is cut through by land drains and watercourses, and a stream running 50 metres to the south-east marks the townland boundary with Garrison. It is this saturated, heavily managed landscape that appears to have both preserved and obscured the monument. When aerial survey teams working on the Bruff photographic survey captured image AP 4/3678 in 1986, they recorded a cropmark, a circular shape made visible because buried ditches and disturbed soil retain moisture differently from the surrounding ground, causing the vegetation above them to grow or ripen unevenly. That fleeting impression from altitude is, to date, the monument's only appearance on record. Subsequent aerial orthoimages taken between 2005 and 2018, including coverage by OSi, Digital Globe, and Google Earth, show nothing at all. The site was compiled by Alison McQueen and Vera Rahilly and uploaded to the national record in October 2020.

For a visitor, there is no feature to locate in the field and no marker to find. The land is private agricultural pasture, and the monument itself offers nothing to the eye at ground level. What the site does offer, if you know where to look on the map, is the slightly vertiginous experience of standing over something real and recorded but entirely invisible, a burial place that only revealed itself once, fleetingly, from the air, and has since returned to anonymity beneath the grass and the drains of a soggy Limerick field.