What gives this particular example its peculiar character is not its earthworks but a well recorded within its banks, a feature that shifted position, at least on paper, between the 1842 and 1937 Ordnance Survey maps. In 1842 it was marked inside the ESE bank; by 1937 it had migrated into the ESE fosse, the defensive ditch. More intriguingly, the OS Memoranda of 20 December 1931 noted that locals were calling the fort "Tober aneeling", a phonetic rendering of an Irish place-name that appears elsewhere as Tubber an eeling. "Tubber" derives from the Irish tobar, meaning a well, suggesting the well was not merely incidental to the site but central enough to name the whole enclosure after it.

The ringfort itself is a fairly typical rath, the term used for an earthen-banked enclosure of early medieval date, generally associated with farmsteads occupied roughly between the fifth and twelfth centuries. This one is roughly circular, measuring 38.3 metres north to south and 34 metres east to west. It has an inner bank rising about 1.2 metres on the interior face, with an intervening fosse, or ditch, reaching a depth of 1.5 metres along the western and southern sections, and a lower outer bank continuing around to the south-southeast. The entrance is a causeway, a raised crossing of the fosse, about 2 metres wide, set into the western side. Trees have taken root on the bank and in the fosse, and the interior is thick with nettles, the reliable signature of a site that has been left to its own devices. About 50 metres to the northwest, in the same field, there is a second circular enclosure, making this a corner of the landscape with rather more going on beneath the surface than the tillage rows suggest.