No marker points to it. It does not appear on the Ordnance Survey's historic mapping. Its existence was first suspected not by archaeologists with trowels, but by someone studying aerial photographs taken during a gas pipeline survey in November 1984, when Bord Gáis Éireann was routing infrastructure across the Irish midlands and south.

The photographs in question, taken at a scale of 1 to 10,000 on the 3rd of November 1984, revealed what analysts interpreted as a possible earthwork site at Knocklong West. Decades later, the feature was confirmed on Digital Globe and Google Earth orthoimages captured between 2011 and 2013, appearing as a cropmark, the ghostly outline that buried or levelled structures leave in growing vegetation when soil moisture and crop height vary above buried features. The shape is sub-rectangular, measuring approximately 25 metres north to south and 15 metres east to west. Adding another layer of interest, a relic watercourse, the trace of an old drainage channel or stream, runs from northeast to southwest and intersects the cropmark along its western side. Whether this watercourse had any relationship to the original function of the enclosure, perhaps as a boundary or a water source, is unknown. The site was compiled by Fiona Rooney and uploaded to the national record in June 2021.

Because the feature exists only as a cropmark in reclaimed pasture, there is little to see at ground level, and the land itself is in agricultural use. The most useful way to examine the site is via the publicly accessible aerial and satellite layers on the Historic Environment Viewer or Google Earth, where the outline can be traced with some patience. Cropmarks of this kind tend to show most clearly in dry summers, when soil moisture differences above buried features cause grass or crops to respond differently to drought stress. Any visit to the broader Knocklong area would need to take into account that this is private farmland, and there is no public access or interpretation on site.