A low earthen bank, rarely more than a few centimetres proud of the surrounding ground, traces a ring roughly 43 metres across. Only in the south and south-west does the bank rise to about a metre, giving the enclosure any real presence in the landscape. Everywhere else, it is the kind of feature that rewards attention rather than announces itself.

What makes the site quietly puzzling is its paper trail, or rather the gap in it. The first edition Ordnance Survey six-inch map, surveyed in 1839, marks the circular feature with a dashed line, the cartographers' way of indicating something they could see but could not confidently classify. By the time the same area was revised between 1946 and 1947, the feature had disappeared from the map entirely, not because it had been destroyed, but apparently because the later surveyors either missed it or chose not to record it. Enclosures of this kind, defined by a single earthen bank and ditch, are common across Ireland and are generally interpreted as early medieval farmsteads, though without excavation the function and date of any individual example remains uncertain. The Knocknew enclosure sits on the highland's northern slope overlooking a river valley, a position that would have made practical sense for a settlement seeking both shelter and a commanding view of the surrounding country.