An oval earthwork once stood here at Coolbaun, measuring roughly thirty metres across, the kind of enclosure that would have been a legible feature of the landscape for centuries. Today it has been levelled, and what remains is a faint memory of itself: subtle undulations in the grass on a south-east-facing slope, with the very slightest suggestion of a curving bank if the light and the season are on your side.

The earthwork was recorded on the first edition of the six-inch Ordnance Survey map, surveyed in 1840, and it was still present, apparently intact enough to map, on the revised edition of 1903 to 1904. At some point between that second survey and the present, it was removed, most likely through agricultural improvement of the kind that quietly erased thousands of such features across Ireland during the twentieth century. Earthworks of this oval or circular form are associated with a broad range of uses across Irish prehistory and the early medieval period, from enclosures around settlement sites to boundaries with ritual or territorial significance, though without excavation it is rarely possible to assign a confident date or function to a levelled example like this one. What the maps confirm is simply that something was there, that it was oval, and that it was substantial enough to be worth recording twice.