The site known as Rathleenan was once a rath, a type of circular earthwork enclosure common in early medieval Ireland, typically formed by a raised bank and ditch and used as a farmstead or small settlement. Roughly 25 metres in diameter, it sat on elevated ground with a steep drop to the north-west and north, and wide views across the rolling, sharply undulating landscape around it. Today, there is nothing at ground level to indicate it was ever there.

The enclosure appears clearly on Ordnance Survey six-inch maps from both 1838 and 1922, marked as a circular, ringfort-sized feature and named Rathleenan. At some point between that later mapping and the present, it was destroyed during land reclamation, a process of agricultural improvement that has accounted for the loss of a great many such earthworks across Ireland. The clearance was thorough: not only was the rath itself removed, but the field boundaries that had abutted and adjoined it were taken out as well, leaving no peripheral trace of its former outline. Approximately 100 metres to the south, a separate enclosure survives, which makes the absence of Rathleenan itself all the more legible by contrast, a presence defined almost entirely by what is missing.