It commands clear sightlines in every direction, which was almost certainly the point. Two streams bracket the site at roughly equal distances to east and west, and the land between them opens out into the kind of low, wet ground that would have made approach visible from a considerable distance.

This is a bivallate rath, meaning a ringfort enclosed by two concentric earthen banks rather than the more common single ring. A rath is a roughly circular enclosure of early medieval date, typically constructed between the sixth and tenth centuries, and used as a defended farmstead for a family of some local standing. The one at Barleyhill is a fairly substantial example: its central platform measures around 27 metres north to south and just under 24 metres east to west, defined by a steeply sloping earthen scarp that still stands between 1.5 and 1.6 metres high on the eastern and western sides. Around the base of this scarp runs a fosse, a defensive ditch, and beyond that the remnants of an outer bank. In places, stone protrudes from the scarp face, particularly to the east and south, which may indicate that the earthwork was once given a stone facing, adding both solidity and presence to its appearance. The fosse survives unevenly: it reads as a shallow depression to the south-west, flattens into something more like a terrace at the north-west, and is interrupted there by an old quarry pit that has bitten into the circuit. A second quarry pit, now grassed over and roughly ten to twelve metres across, lies just ten metres to the south of the rath itself, a reminder that the site has been worked around, if not directly disturbed, in more recent centuries. A modern field fence cuts across the interior, and hawthorn and blackthorn have taken hold on the southern and south-western scarp, their roots no doubt contributing to the slumping visible in the northern part of the enclosure. What remains is eroded and partial, but the essential form of the thing is legible: a deliberate, carefully engineered piece of early medieval landscape management, still sitting where it was built.