At the northern foot of Knockaulin hill in County Kildare, a circular earthwork sits quietly in pasture, its stepped profile setting it apart from more familiar burial mounds. Unlike a simple round barrow, this monument is built in distinct layers: a low central mound, roughly 18 metres across and rising between 0.6 and 1.6 metres above the surrounding ground, is ringed first by a broad flat berm, a shelf-like platform separating the mound from the outer ditch, and then by a wide fosse, the ditch that gives the whole structure its stepped appearance in cross-section. The overall monument measures around 44 metres across, making it a substantial presence in the landscape even if its low profile means it does not announce itself from a distance.

The earthwork sits on an east-facing pasture slope, and its position is not accidental. Roughly 630 metres to the south rises Dún Ailinne, one of the great ceremonial hillforts of prehistoric Ireland, a site associated in early Irish tradition with the kings of Leinster. The proximity suggests this barrow, wherever it falls in the long sequence of activity around Knockaulin, was placed within a landscape already freighted with significance. The monument has been partially dug out at some point, and the western side of the berm has been heavily poached, meaning animal traffic has broken up and softened the ground surface there, obscuring the original form. The outer fosse varies in width, narrower at its base in the south and opening more broadly at the north, which may reflect either original design or differential erosion over the centuries.