This roughly rectangular enclosure measures approximately 39 metres from northwest to southeast and 29 metres from northeast to southwest. The site is defined by an earthen bank that rises about half a metre on the inside and 0.7 metres on the outside, accompanied by an external fosse, or defensive ditch, that reaches depths of 0.2 metres and spans up to 3.5 metres at its widest point.

The earthworks have suffered considerable damage over the centuries, particularly along the eastern and southern sides where livestock have heavily eroded the bank through repeated trampling. A modern field boundary now runs alongside the fosse on the northwestern edge, marking how contemporary agricultural use has adapted to these ancient earthworks. Despite the erosion, the basic form of this defensive structure remains clearly visible in the landscape.

Moated sites like this one at Clonrobin were typically constructed during the Anglo-Norman period in Ireland, roughly from the 12th to 14th centuries. These fortified farmsteads served as administrative centres for agricultural estates, providing both security and status for their inhabitants. The combination of bank and fosse would have originally been more imposing, possibly topped with a timber palisade, creating a formidable barrier whilst also draining the surrounding land for agricultural purposes.