What makes the Killydrutan court tomb worth attention is its unusual intimacy of scale. Court tombs, a type of megalithic monument built during the Neolithic period roughly five thousand years ago, typically feature a forecourt area where communal rituals were likely conducted before a roofed gallery containing the dead. Here, that court is notably shallow, formed by just two stones flanking the entry jambs, one on each side. It is a minimal gesture towards a form that elsewhere in Ireland can be far more elaborate.

The burial chamber itself measures 3.7 metres in length and just 1.1 metres in width, oriented along an east-west axis. Its walls survive as a single upright stone along the southern side and two stones along the northern, enough to give a clear impression of a long, narrow corridor cut into the hillside. Towards the western end, a stone set transversely across the gallery suggests the space was once divided into segments, a feature seen in other court tombs where different deposits or successive burials may have been separated from one another. A short distance to the north, three large flat stones lying some four metres from the chamber are thought to be remnants of a kerb, the low stone border that would originally have defined the outer edge of the cairn mound covering the whole structure.