It runs for more than 90 metres, shifting direction as it goes, first heading northward before curving back on itself toward the water, then continuing away to the northeast. The bank is no modest ridge: it reaches 15 metres wide on its western side and broadens to 20 metres where it approaches the stream most closely, rising to a height of 1.5 metres at that point. That is a considerable volume of earth to move, and the question of why someone moved it has no straightforward answer.

The most obvious modern candidate, a flood-relief embankment of the kind built along Kerry waterways in the twentieth century, does not hold up on inspection. The stream beside which it sits is a minor tributary of the River Lee, too slight to have warranted large-scale drainage intervention. This rules out one category of earthwork common in the Irish countryside but leaves the original purpose open. The meandering, curving form is also unusual; purely functional boundary banks tend toward straighter lines. The site sits in the same field as a separate recorded feature, suggesting that this corner of Knockavinnane accumulated some significance in the past, though the nature of that significance remains unclear. The earthwork was recorded by Michael Connolly during a survey of the Lee Valley area carried out in 1996 and 1997, and it was noted then that its function could not be confidently assigned.