These maps, produced from the mid-nineteenth century onward, were remarkably thorough in recording earthworks across the Irish countryside, so their silence on a particular site usually means it was either too subtle to catch a surveyor's eye or was genuinely overlooked. The rath at Derrycallaghan, in County Tipperary, falls into that quietly puzzling category.

The site was identified not through ground survey but from a Digital Globe aerial photograph taken in November 2011, which revealed a circular enclosure approximately 32 metres in diameter, defined by an earthen bank, an external fosse (a defensive ditch dug around the perimeter), and what appears to be a suggestion of a further outer bank beyond that. Ringforts, or raths, were the most common form of rural settlement in early medieval Ireland, typically consisting of a raised circular area enclosed by one or more earthen banks and ditches, and used as farmsteads by families of varying social rank. What makes the Derrycallaghan example particularly interesting is its setting and company. A stream and a lime-kiln lie just 25 metres to the west, and within 300 metres in various directions there are at least two other ringforts and a further enclosure. That density of earthworks in a relatively small area points to a landscape that was once intensively organised and occupied, though modern housing now sits just 15 metres to the north of this particular site.

The earthwork sits in grassland, and its survival, however faint, alongside a cluster of related monuments suggests that this corner of Tipperary repays careful attention for anyone interested in the texture of an early medieval farming landscape, even if much of what was once there is now only legible from the air.