Where a ringfort once stood on low-lying wet grassland in County Westmeath, no bank, no ditch, no trace of raised earth remains. The site survives only as a cropmark, a subtle darkening of vegetation in a roughly sub-rectangular shape measuring approximately 26.5 metres northwest to southeast and 39 metres northeast to southwest, ghosting the outline of the enclosing element that was long ago levelled into the surrounding field.

Ringforts are the most numerous monument type in the Irish landscape, earthen or stone enclosures typically associated with early medieval farming settlements, built to define a household's space and protect livestock. Most survive at least partially above ground. At Cullenhugh, even that modest presence has been erased. What we know of the site's former shape comes largely from nineteenth-century cartography. The 1837 Ordnance Survey Fair Plan map recorded it as an irregular-shaped enclosure and annotated it simply as "fort". The same survey's six-inch map placed it immediately north of a laneway that led to a farm building lying to the west, a configuration suggesting the earthwork had already been absorbed into working agricultural land by the time the surveyors arrived. By some point after that, the enclosing bank was levelled entirely, leaving only the buried shadow of its footprint to register in the vegetation above.

The cropmark that now defines the site is the kind of feature best observed from the air or in dry summers, when differential moisture retention in the soil causes the vegetation over buried features to grow or colour differently from the surrounding ground. At field level, on a damp Westmeath day, there is simply grass.