It is only when you begin to read the shape carefully that something deliberate becomes apparent: the enclosure, around 41 metres in diameter, has been engineered to sit level despite the fact that the hillside beneath it does not.

Enclosures of this kind are among the most common archaeological monuments in Ireland, yet they remain among the least understood. They are generally assumed to date from the early medieval period, roughly the fifth to the twelfth centuries, and may have served as enclosed farmsteads, the ringfort being the most familiar type. What makes this particular example quietly interesting is the care taken in its construction. The ground inside slopes downward toward the south-east, so the builders raised the bank on the southern and eastern sides, reaching a maximum height of about 1.5 metres, to compensate for the natural fall of the hillside. The result is an interior that would have sat more or less level, enclosed and usable, on what is otherwise a gentle south-facing slope. It is a small but telling piece of practical engineering, achieved entirely in earth.