The monument at Knockaunavaddreen is classed as a kerb circle, a type of prehistoric enclosure in which upright stones, or orthostats, are set around the perimeter of a roughly circular area, sometimes surrounding a burial or acting as a ceremonial boundary. Here the circle measures approximately twelve metres across, which gives it a modest but definite presence on the hillside.

Four stones can be identified with some certainty. Two stand in opposition across the circle, one to the north at just over a metre in height, one to the south slightly shorter, and two smaller examples occupy positions to the east of each of these uprights. A third stone, now nearly prostrate, would stand around 1.4 metres if righted. The fourth is very small indeed, barely forty centimetres high. What makes the site particularly melancholy is what has been lost in the decades since it was first formally recorded. Several other perimeter stones and flat slabs that were still visible in the early 1970s have since been gathered up and dumped into the interior, blurring whatever spatial logic the original arrangement may have held. Seán Ó Nualláin, writing in 1984, noted the site's uncertain character and suggested a possible relationship with comparable monuments at Cuppage and Gortnahown, though precisely what that relationship might be remains an open question.