Others earn it by disappearing entirely. The ringfort at Knockane, in County Limerick, belongs firmly to the second category. What was once a rath, a type of enclosed farmstead typically consisting of an earthen bank and ditch forming a rough circle, once sat on a gentle west-north-westerly facing slope in what is now open pasture. By the time anyone came to look for it properly, there was nothing left to find.

The monument was recorded on the 1924 Ordnance Survey six-inch map as an embanked roughly circular enclosure approximately forty metres in diameter. Ringforts of this kind were built throughout Ireland during the early medieval period, serving as defended homesteads for farming families, and they survive in their thousands across the Irish countryside. This one did not survive. When Denis Power carried out an inspection, compiled and uploaded to record in August 2011, he found no trace of the monument whatsoever. The enclosure visible on the map had been levelled, the pasture rolling over it with no visible interruption.

There is, in a quiet way, something instructive about a scheduled visit to a site that no longer exists. The Knockane rath is still listed in the archaeological record precisely because the 1924 map caught it before it was gone, preserving at least the outline of what had been there. Visitors to this part of Limerick will find working farmland rather than any earthwork, and the slope itself gives little away. The value here is less in standing at the spot than in understanding how much of Ireland's early medieval landscape has been quietly absorbed back into agriculture over the past century, with only a line on an old map left to mark the fact that something was once there at all.