Each is modest in scale, around twelve metres long, five and a half metres wide, and rising perhaps a metre and a half from the ground, but what distinguishes them is the detail around their edges: a line of stones traces the perimeter of each mound, suggesting they were once revetted, meaning faced or reinforced with stonework to hold their shape against the slow pressures of weather and time. Between them stands a single small upright of limestone, its purpose unrecorded.

In 1933, a scholar named Mac Domhnaill visited and described what he saw simply as "two grave mounds". That plainness of description is itself telling. Burial mounds of this kind, raised over the remains of the dead and sometimes edged with kerbing stones to define the sacred boundary of the monument, appear across Ireland in various forms from the prehistoric period onwards. Whether these particular mounds date to prehistory, the early medieval period, or some other era entirely, the available record does not say. What remains is the physical fact of them: two contiguous earthen forms, shaped by human hands, placed deliberately close to one another in the centre of a small Atlantic island, with a stone set upright in the ground between them.