This one does the opposite. A ring barrow in Knockainy West, County Limerick, went unrecorded on Ordnance Survey historic maps entirely, and remained effectively unknown until a low-altitude aerial photograph, taken on a January morning in 2003, caught the faint shadow of a circular earthwork pressed into the wet pasture below. It is the kind of discovery that says more about the limitations of ground-level surveying than about any particular obscurity of the site itself.

A ring barrow is a prehistoric burial monument, typically consisting of a low central mound surrounded by a ditch and sometimes an outer bank, the whole arrangement forming a rough ring when seen from above. This example, identified in aerial photograph ASIAP 348, 7 and later confirmed through Ordnance Survey Ireland orthoimagery taken between 2005 and 2012 as well as a Google Earth image from April 2006, measures approximately eleven metres in diameter. It sits in what the record describes as improved rough wet pasture, cut through by land drains and watercourses, around 65 metres south-west of the townland boundary with Knockainy East. A separate ring barrow, catalogued as LI032-310, lies just two metres to the south-east, suggesting this corner of south Limerick holds a small cluster of prehistoric funerary activity, though both monuments have so far slipped beneath the notice of the historic mapping tradition. The record was compiled by Alison McQueen and Vera Rahilly and uploaded to the national monuments database in November 2020.

Because the monument is visible primarily as a cropmark, the ground itself offers very little to the casual eye. Cropmarks appear when buried features affect the growth of surface vegetation differently from the surrounding soil, and they tend to show most clearly in dry summers when grass over a buried ditch stays greener, or over a compacted mound turns parchment-coloured earlier. The wet, drained pasture here makes the site difficult to read in person at most times of year. The nearest orientation point is the townland boundary between Knockainy West and Knockainy East, and the site lies on private farmland, so any visit would require landowner permission. For most people, the aerial and satellite imagery that revealed this monument in the first place remains the most legible way to see it.