Its existence was revealed only through aerial photography, where a faint curving cropmark traces the outline of a ditch barrow roughly eight metres in diameter. A barrow, in its simplest form, is a burial mound or enclosing ditch constructed during the prehistoric period, often marking the grave of an individual of some significance. This one is visible only from a particular arc of sky, appearing on aerial photographs taken from the south-southeast, south, and west, but disappearing from any other angle.

Cropmarks form when buried features affect the growth of vegetation above them. A filled ditch, richer in moisture and organic material than the surrounding soil, will often produce a slightly lusher or differently tinted stripe of grass or crop overhead, betraying its presence to a camera at altitude even when nothing is visible at ground level. That is how this small circular feature came to be documented, identified through Digital Globe aerial photography and brought to wider attention by Brian Doyle. What makes the Knightswood barrow particularly interesting in its context is its proximity to a larger possible ceremonial enclosure located approximately eighty metres to the north-northwest. The two features together suggest this corner of Westmeath grassland may have held some kind of ritual or funerary significance in the prehistoric landscape, though the precise relationship between them remains unconfirmed.