The cause is a trackway running east to west directly alongside the fort at that point, which has effectively inflated the apparent height of the bank by lowering the ground beside it. The result is a structure that reads differently depending on which direction you approach from.

The rath at Knoppoge is a univallate ringfort, meaning it has a single enclosing bank rather than the concentric rings found at more elaborate sites. Ringforts of this type were the most common form of rural settlement in early medieval Ireland, typically serving as enclosed farmsteads for a family and their livestock. This one measures 43 metres across in both directions, making it a reasonably substantial example. Its bank averages around 6 metres wide, and to the north-east it appears to be built from a combination of earth and stone rather than earth alone. The interior sits at roughly the same level as the surrounding land on most sides, with the exception of the northern portion where the adjacent trackway complicates the relationship between the enclosure and its immediate landscape. These details come from the North Kerry Archaeological Survey, compiled by C. Toal and published in 1995.