It is a rath, the Irish term for a ringfort, one of the most common monument types in the Irish landscape, yet this particular example at Lisgub has been worn down to the point where much of what once defined it has become ambiguous ground. Ringforts were enclosed farmsteads, typically of early medieval date, built by a single family or household and bounded by one or more banks and ditches to protect livestock and mark out a domestic territory. At Lisgub, the enclosure measures approximately 54 metres north to south and 51 metres east to west, making it a reasonably substantial example, though that scale is now easier to read on a plan than to feel on the ground.

What survives is uneven. The bank is still legible along the southern arc, from the south-east around through south to south-west, but elsewhere the boundary has reduced to little more than a scarp, a natural-looking slope that only betrays its artificial origin when you know to look. The external fosse, a ditch that would once have run around the outside of the bank, has vanished entirely along the northern and eastern stretches. What remains is a partial outline, enough to confirm the site's original shape and purpose, but not enough to convey the enclosed, inhabited world it once contained.