In the townland of Meadagh, in County Limerick, that is precisely what appears to have happened. A circular earthwork, the kind that might once have been a ring fort or small enclosure, sat quietly in reclaimed pasture just west of a watercourse marking the boundary with the neighbouring townland of Milltown. It was never marked on Ordnance Survey Ireland's historic maps. For most of its existence, at least in any documented sense, it simply was not there.

The site came to light not through fieldwork but through the sky. An aerial photographic survey carried out in 1986, centred on the Bruff area of County Limerick, picked out what surveyors catalogued as a possible enclosure, recorded as Bruff 46. Aerial survey has long been one of the most effective tools for spotting earthworks invisible at ground level, particularly in pasture land where subtle differences in grass growth or soil colour can betray buried features below. Decades later, Digital Globe satellite imagery taken between 2011 and 2013 still showed something: a scrub-covered circular form, cut across at its northern edge by a track running roughly north-east to south-west, with Milltown House sitting about 240 metres to the north-east. By March 2017, however, a Google Earth image showed the ground at that location had been excavated. By June 2018, a follow-up image showed no surface remains whatsoever.

There is, in a practical sense, nothing left to visit. The site as recorded by Fiona Rooney and uploaded to the survey database in May 2021 exists now only in the archival record: the 1986 aerial photograph, the successive satellite images charting the earthwork's slow disappearance, and the coordinates placing it in that strip of reclaimed pasture beside the townland boundary stream. For anyone interested in the archaeology of County Limerick, the Bruff aerial photographic archive itself is the place to look, offering a glimpse of what the landscape held before ground-level changes erased it.