In the townland of Treanmanagh, a relic field system covering roughly 200 metres on its northeast-to-southwest axis and 150 metres across has survived, not as upstanding earthworks or stone walls, but largely as a series of drainage ditches, the faint skeletal remains of a working agricultural landscape that nobody has been able to date with any precision.

What makes this site particularly curious is its absence from the Ordnance Survey Ireland historic maps, meaning it left no trace in the cartographic record that has guided Irish historical research for nearly two centuries. Its existence only became apparent through aerial photography, specifically the Bruff aerial photographic survey, which recorded it as reference Bruff 14, AP 4/3625, and identified it as a relic field system. Two enclosures, recorded separately under the reference numbers LI024-205 and LI024-207, sit along its western and southern margins. The townland boundary with the neighbouring townland of Derk lies around 500 metres to the west. The underlying ground is poorly drained reclaimed grassland, which may help explain both the reliance on drainage ditches to define boundaries and the difficulty of reading the site at ground level. Compiled by Edmond O'Donovan and uploaded to the record in September 2020, the site continues to be visible on aerial imagery, including a Google Earth image captured in November 2018 and Digital Globe orthoimages from 2011 to 2013, with the southern extent of the old field boundaries also discernible on Ordnance Survey Ireland orthoimages taken between 2005 and 2012.

This is not a site with a visitor path or an interpretive panel. Its legibility depends almost entirely on aerial or satellite imagery, and anyone curious enough to look it up on Google Earth or the relevant OSi orthoimage layers will find more there than they would standing in the field itself. The surrounding landscape is flat and agricultural, and the drainage-ditch boundaries that define the system would read to most eyes as nothing more than ordinary field drainage. Cross-referencing the Bruff survey image alongside a current satellite view is the most rewarding way to appreciate how much information lies just beneath an apparently unremarkable piece of Irish farmland.