Not through excavation or chance discovery during building work, but through the grass growing above it, which turned a slightly different shade at the right time of year and under the right conditions, and was caught on camera from orbit.

What the satellite image recorded is a cropmark, a phenomenon where buried features such as ditches or walls affect how moisture moves through the soil, causing the vegetation above to grow differently, producing outlines that are invisible at ground level but legible from the air. In this case, a rectangular shape measuring approximately 14 metres by 13 metres, defined by what appears to be a ditch, showed up in a Google Earth photograph taken on 29 March 2012. The record was compiled by Caimin O'Brien, drawing on details provided by Jean-Charles Caillère, and was uploaded to the national record in January 2022. What the enclosure originally contained, or when it was constructed, is not yet known. The shape alone, modest and nearly square, is what survives.

Because this site exists essentially as a mark in aerial photography rather than a visible feature on the ground, there is little for a visitor to see directly. The townland of Coolnanoglagh lies in County Limerick, and the cropmark itself would be indistinguishable from any other patch of farmland to someone standing in the field. The value here is in understanding what the record represents: that the Irish landscape holds an enormous number of sites known only through remote sensing, logged carefully but not yet investigated. The Google Earth orthoimage remains the clearest view of this particular enclosure, and it is worth seeking out simply to appreciate how much archaeology is still, in the most literal sense, underground.