They are tree-rings, built deliberately to frame and protect ornamental or specimen trees as part of a designed estate landscape, and they are quietly strange things: low, careful, geometrically precise constructions whose purpose is almost invisible unless you know what you are looking at.

Each enclosure is roughly eleven and a half metres in diameter, defined by a wall of rectangular stones laid two courses high, between one and one point two metres wide and rising to somewhere between half a metre and just under a metre. Two of the three circles have domed interiors, raised about forty centimetres at the centre, which would have aided drainage around the base of a planted tree and given the whole structure a subtly sculptural quality. Tree-rings of this kind were a feature of eighteenth and nineteenth century demesne planting in Ireland, where landowners shaped their grounds according to fashionable landscape design. The rings served a practical purpose, keeping grazing animals from damaging young or valued trees, but they were also built to be seen, given a neatness and solidity that plain post-and-rail fencing would never have provided.