The raised platform, roughly fourteen metres across in either direction, sits in the south-eastern quadrant of a rath, the circular earthwork enclosure that served as a farmstead for an early medieval Irish family, typically dating to somewhere between the sixth and twelfth centuries. The mound is modest, lifting no more than sixty-five centimetres at its highest eastern edge, but its subrectangular outline and the remnant of a low bank along its western side suggest the deliberate shaping of a domestic space rather than any natural feature of the terrain.

The bank itself, about 1.7 metres wide and surviving to only around twenty centimetres in internal height, would once have helped define the boundary of the structure it enclosed. A second house lies roughly ten metres to the north-west, which points to the rath having supported more than one building at some point in its use. That kind of internal arrangement, with separate structures sharing an enclosure, is not unusual within Irish raths, where outbuildings, byres, and additional dwellings often clustered together behind the main earthen boundary bank. What makes the Ballygreighan example quietly interesting is how legible it remains despite centuries of weathering and agricultural activity, the platform holding its shape well enough that the dimensions can still be measured and mapped.