This ring barrow at Ballyphilip in County Limerick does the opposite. It survives not as a visible rise in the ground but as a cropmark, a faint circular shadow roughly 9.5 metres in diameter that shows up in aerial photography when differential crop growth above buried features betrays their outline from above. At ground level, in the wet, low-lying pasture cut through by land drains and watercourses, there is nothing obvious to see at all. A ring barrow, broadly speaking, is a prehistoric funerary monument, typically a low burial mound encircled by a ditch and sometimes an outer bank. What survives here is less than a silhouette.

The monument was first identified during the Bruff aerial photographic survey in 1986, appearing in survey image Bruff 15706 as a small circular cropmark. It does not appear on any Ordnance Survey Ireland historic maps, which suggests it was never prominent enough above the ground surface to be recorded by earlier cartographers. OSi orthoimagery taken between 2005 and 2012 also captured the cropmark, but by March 2017 a Google Earth image of the same area showed nothing at all, illustrating how dependent such traces are on the right soil conditions, the right season, and the right growing crop overhead. Ballyphilip is not an isolated case here; the site sits within a larger complex of ring barrows, with a second ring barrow recorded just 3 metres to the north-east and an enclosure some 30 metres to the east-south-east, suggesting that this low, damp corner of Limerick was once a place of some significance in the prehistoric landscape. The monument record was compiled by Alison McQueen and Vera Rahilly and uploaded in September 2020.

For anyone curious enough to visit the general area, the site lies in ordinary farmland and access would require landowner permission. The pasture here is wet, and the ground is cut by drainage channels, so the going can be heavy depending on the time of year. There is, in any practical sense, nothing to stand over and observe. The real interest lies in what the aerial record shows, and in the knowledge that the field underfoot is more layered than it appears. Comparing the 1986 Bruff survey image against the blank 2017 Google Earth view gives a reasonable sense of how provisional our picture of such places actually is.