The site measures roughly 21.6 metres north to south and 21 metres east to west, its boundary surviving as a slumped scarp, a gradual earthen slope rather than the crisp bank it would once have been. The southern side of this scarp is noticeably more pronounced than the northern, rising to around 1.6 metres compared to just 0.5 metres at the north, which points to something deliberate in the original construction: the builders appear to have built up the southern half of the enclosure to level out what is naturally a sloping site. The result is an interior that still tilts gently downward from northwest to southeast, a quiet echo of the engineering problem someone tried to solve perhaps a thousand years ago.

Ringforts, known in Irish as raths when they are earthen rather than stone, were the most common form of rural settlement in early medieval Ireland, typically serving as enclosed farmsteads for a single family or small community. What makes Ranagissaun particularly worth noting is that it does not stand alone. A second rath sits approximately 300 metres to the east-northeast in the same field, and a third lies around 200 metres to the northwest. The clustering of three such enclosures within such a compact area raises questions about how this landscape was organised and occupied, whether by related families, successive generations, or a more complex arrangement of landholding that the earthworks alone cannot answer. Within the interior of the Ranagissaun fort, a faint circular rise of three to four metres in diameter is visible in the eastern half, though its purpose remains uncertain.

The site sits on a southeast-facing slope with open views stretching to the south, west, and north, with higher ground rising away to the northeast and east. The surrounding pasture has been reclaimed, meaning the landscape around the fort has been substantially altered over time, which makes the survival of three raths in the same field all the more striking.