This one earns it by having vanished entirely. On a low north-to-south ridge in the townland of Rooskagh East, County Limerick, there once stood an embanked oval enclosure, roughly 40 metres along its longer axis and 30 metres across. It is the kind of earthwork that might have served any number of purposes over the centuries, a field boundary, a ringfort enclosure, a stock enclosure of uncertain age. Today, there is nothing there at all.

The enclosure was recorded on the Ordnance Survey six-inch map of 1924, which captured it as a clearly defined oval earthwork set into the pasture on the ridge top. Embanked enclosures of this type are relatively common across Limerick and the wider Munster landscape, often representing the remains of ringforts, which were enclosed farmsteads typically built during the early medieval period, roughly between the fifth and twelfth centuries. Whether this particular example was of that tradition or something else entirely is now impossible to say. When Denis Power compiled the site record, uploaded in August 2011, he noted that the monument had been levelled and that no trace of it was evident on inspection. The OS map, in other words, is the only witness left.

The site sits in agricultural pasture, and there is no feature visible at ground level to reward a visit in the conventional sense. What remains is the ridge itself, running north to south, and the quiet fact that a mapped monument once occupied its crest. For anyone interested in how quickly the physical record can be erased, and in what the 1924 six-inch OS sheets preserve that the landscape no longer does, Rooskagh East is an instructive if sobering case. The maps themselves, freely available through the Irish Historic Maps viewer, show the enclosure clearly enough for a visitor to orient themselves on the ground and understand precisely what has been lost.