A slightly raised circular platform, roughly fifty-two metres across at its widest, enclosed by an earthen bank and a surrounding ditch, it is the kind of feature that the Irish landscape holds in abundance yet which most people never learn to read.

What lies here is a rath, the most common type of ringfort found across Ireland, typically dating from the early medieval period, roughly 500 to 1000 AD, and thought to have served as a farmstead enclosed for the protection of livestock and family. The bank at Ballinaboy still stands to about one and a half metres in height, and the external fosse, a defensive ditch dug around the outside of the bank, survives to a depth of around 0.85 metres along the eastern, south-western, western, and north-western sides. There are two gaps in the bank, one to the east at about two and a half metres wide, another to the west-south-west at two metres, but the principal entrance, at four metres across, faces north-north-west. That surviving entrance width is notable; four metres is broad enough to have admitted cattle, which is entirely consistent with how these enclosures functioned as working agricultural spaces rather than purely defensive ones.

The earthwork sits in grassland, which is often the best condition in which to find surviving raths. Arable ploughing over the centuries has levelled many comparable sites across the country, so those that ended up under permanent pasture have a much better chance of retaining their original profile. Walking the perimeter, the slight elevation of the interior platform becomes apparent underfoot before it becomes obvious to the eye.