Most ringforts, the roughly circular earthen enclosures that dot the Irish countryside as remnants of early medieval farming settlements, are defended by a bank and a fosse, the latter being a ditch dug to reinforce the barrier. At Moandoolish, however, there is an additional element inserted between the two: a berm, a flat platform of ground separating the fosse from the outer bank. That detail, unusual enough to warrant specific note, gives the site a more elaborate defensive profile than the standard design.

The fort is bivallate, meaning it has two concentric earthen banks rather than one, and measures approximately 70 metres in diameter. The inner bank stands up to around two metres in external height, and the partially waterlogged fosse beyond it runs to about half a metre in depth. Beyond that fosse lies the berm, between roughly eight and ten metres wide, and then the outer bank. On the eastern, south-eastern, and southern sides, that outer bank has been worn down to little more than a scarp. In the southern and western parts of the interior, the ground slopes inward toward the bank, creating a shallow internal fosse of its own, an unusual secondary feature. The fort sits on a natural rise in otherwise level terrain, with wet, rushy pasture lying to the east.

The interior today is heavily overgrown with scrub, thorn bushes, and brambles, and a post-and-wire fence divides the northern section east to west, with a rough farm track running along its southern side. The monument is in agricultural land, and the vegetation makes close inspection of the interior difficult. What remains most legible from the outside is the earthwork profile itself, particularly the sequence of bank, fosse, berm, and outer bank on the less-eroded northern and western sides.