What makes it unusual is not just its age but its layered geometry: an inner oval, roughly 36 metres on its longer axis, set within a larger outer enclosure of around 60 metres, the two separated by a gap of between five and thirteen metres. That outer ring is broadly sub-square rather than circular, with curving angles to the east and south, giving it an irregular, almost improvised outline that distinguishes it from the more regular ringforts found elsewhere in the Irish midlands.

Enclosures of this type are generally understood as the remains of early medieval settlement, the ringfort being the most common form of enclosed farmstead in Ireland between roughly the fifth and twelfth centuries. A double enclosure, where an inner ring is wrapped by a second outer one, is less common and is sometimes associated with higher-status occupation, the additional circuit suggesting either greater defensive concern or a need to manage livestock and activity in a more organised way. The Oldtown example was already mapped by the Ordnance Survey in 1839, and by the time of the 1948 revision it was recorded again, by which point the outer enclosure had become absorbed into an ordinary field boundary, its ancient function dissolved into the working agricultural landscape around it. Satellite imagery shows trees growing along the perimeters now, and the interior lies under grass.