It does not appear on the Ordnance Survey's historic maps, and nothing marks it out on the ground. What gives it away, if anything gives it away at all, is the crop itself: a faint circular shadow in the vegetation, legible only from the air, roughly forty metres across from east to west and thirty-eight metres from north to south.

This kind of feature is known as a cropmark, and it forms when buried structures, walls, ditches, or fills of disturbed earth affect how plants grow above them. Crops over a buried ditch tend to grow taller and greener, drawing on the deeper, moister soil; crops over buried stonework may be stunted. From the ground, the difference is nearly imperceptible. From altitude, the pattern becomes clear. It was aerial photography reviewed by the Archaeological Survey of Ireland in 2003 that first identified this enclosure at Lissowen, recorded under reference ASIAP 354, 20. Later orthophotos taken between 2011 and 2013 via Digital Globe, and a Google Earth image from November 2018, confirmed that the circular cropmark remains visible, pressing up against a field boundary to its south-east. A possible ringfort, a separate monument recorded as LI016-021, lies approximately eighty-five metres to the south-east of the enclosure. Ringforts, the most common archaeological monument type in Ireland, were typically circular enclosures of earth or stone used as farmsteads during the early medieval period, roughly the fifth to the twelfth centuries. Whether this enclosure at Lissowen is related to that site, or belongs to an entirely different period of activity, has not been established.

There is no formal public access to the site, and nothing on the ground reliably marks its location for a visitor. The monument was compiled in the national record by Alison McQueen and Vera Rahilly, uploaded in July 2020, as part of ongoing efforts to document sites identified through remote sensing rather than fieldwork. For anyone with an interest in landscape archaeology, the broader area of County Limerick repays attention on aerial imagery platforms; the density of cropmarks across the region reflects centuries of activity that ordinary maps and field boundaries do not begin to capture.