This medieval earthwork forms an almost perfect circle, roughly 30 metres across, though its southeast corner breaks the pattern with a distinctly square edge. The site occupies a clearing in mixed woodland, its boundaries still clearly marked by centuries-old earthen defences.

A substantial bank encircles the site, standing about half a metre high on the inside but dropping 1.6 metres on the outer edge, creating an impressive defensive barrier some 5 to 6 metres wide. Beyond this lies a flat-bottomed moat, its width varying between 6 and 6.5 metres at the top, narrowing to about 3 metres at the base. The moat’s depth varies considerably; at the southwest it’s barely 40 centimetres deep, whilst at the northeast it plunges to 1.7 metres. A stone-reinforced causeway, just over 2 metres wide, provides access from the northeast, its masonry revetment still intact after centuries of weathering.

Archaeological excavations conducted in 2004 explored two fields about 20 metres west of the site but yielded no additional medieval material, suggesting the moated area was relatively isolated rather than part of a larger settlement complex. These moated sites, common across medieval Ireland, typically served as fortified homesteads for Anglo-Norman settlers or prosperous Irish families during the 13th and 14th centuries. The Kilclammon example, with its well-preserved earthworks and strategic valley location, offers a glimpse into how medieval communities balanced defensive needs with access to water and agricultural land.