This one, in reclaimed pasture outside Gormanstown in County Limerick, does none of that. It exists, for most practical purposes, as a ghost pressed into the soil, a roughly circular outline approximately 22 metres in diameter that only becomes legible from the air, and only then under the right conditions. No ordnance survey historic map ever recorded it. It came to light not through excavation or antiquarian curiosity, but through aerial photographs taken by Bord Gáis Éireann on the 3rd of November 1984, during routine survey work for the gas network.

What those photographs captured was a cropmark, the kind of faint signal that buried archaeology leaves in growing vegetation when differential moisture or soil disturbance causes crops or grass to grow at slightly different rates above buried features. The circular outline has since reappeared on an Ordnance Survey Ireland orthophoto taken sometime between 2005 and 2012, on a Digital Globe image from 2011 to 2013, and on a Google Earth image dated 14 September 2019, each time as a faint but legible ring in the pasture. The monument sits 125 metres northwest of Gormanstown Castle, with a separate enclosure recorded immediately to its northeast. The fact that a drainage channel running northwest to southeast now cuts across the northeastern arc of the circle suggests the landscape has been substantially managed over time, which may partly explain why the earthwork itself was reclaimed and levelled into the surrounding fields without ever leaving a trace in the cartographic record. The site record was compiled by Martin Fitzpatrick and uploaded in May 2021.

For anyone curious enough to seek it out, the site offers no visible surface feature to stand beside or photograph at ground level. The most useful approach is to consult the publicly available orthoimages referenced in the National Monuments Service record, where the cropmark is faintly but genuinely visible as a circular trace in the field. The land lies in private agricultural use, so access would require landowner permission. The cropmark itself is most legible in dry summers, when soil moisture differences are most pronounced and the buried archaeology beneath speaks most clearly through the grass above it.