At Baile An Oidhre, in the west Kerry Gaeltacht, the first edition of the Ordnance Survey map records a circular enclosure on a fairly level stretch of ground, less than a hundred metres from the Glennahoo river. The Fair Plan, an earlier cartographic document used in the preparation of OS maps, even gave it a name: "Fort". Today, nothing remains above ground.

The feature would originally have been a rath, the Irish term for a ringfort, a type of enclosed farmstead common throughout Ireland from roughly the early medieval period. These were typically circular earthen banks, sometimes with an external ditch, enclosing a homestead and its outbuildings. Thousands survive across the country in varying states of preservation, but a great many more have been levelled over centuries of farming, drainage works, and land clearance. The one at Baile An Oidhre appears to belong to this latter category. By the time J. Cuppage documented the Dingle Peninsula in the 1986 archaeological survey of the Corca Dhuibhne region, the site had already left no visible trace. Its existence is known only because somebody, at some point in the nineteenth century, thought it worth recording on a map.