What makes it worth a second look is what it almost certainly is not. At first glance, the remnants of a scarp and a stone-faced outer ditch might suggest an ancient enclosure, the kind that dots the Irish countryside as ringforts or cashels. But an inspection carried out in 2001 concluded that this feature is probably a tree-ring, a designed landscape element rather than anything prehistoric or defensive.

Tree-rings were ornamental plantings, typically of the eighteenth or nineteenth century, in which trees were arranged in a circle or oval to create a visual feature within a designed demesne or estate landscape. They were sometimes functional as shelter belts, sometimes purely aesthetic, and they occasionally incorporated earthen or stone boundaries to define and protect the planting. The Farranmacfarrell example sits roughly thirty metres south of what is recorded as a possible seventeenth-century house, suggesting the property had a long history of occupation before any ornamental landscaping took place. The oval area measures somewhere between twenty-five and thirty metres in diameter. Its western side retains a scarp around 0.8 metres high, with a fosse or ditch beyond it, nearly four and a half metres wide, its outer face vertical and stone-faced. The feature was entirely absent from the Ordnance Survey six-inch map of 1837, but by the 1913 edition it appears as a hachured oval enclosure, with what was mapped as a curving field boundary running from the south-west around to the north. That boundary is now understood to be the outer edge of the ditch. Trees survive on the southern and western perimeter, though the feature as a whole is poorly preserved.