A slight rise in the ground is all most walkers would notice at surface level, yet from above the circular plan reasserts itself with surprising clarity, the flattened earthworks reading as a shadow pressed into the field.

A rath, as this type of monument is known, is an early medieval farmstead enclosed within one or more earthen banks and ditches, built to define territory, provide security for livestock, and signal the status of whoever lived within. At Garranes the enclosure measured roughly sixty metres in diameter, a respectable size. The northern arc of the original bank still survives to a height of about two metres, partly because it was folded into the field fence system over time, its bulk made useful rather than removed. A shallow fosse, the outer ditch that would originally have reinforced the bank, remains faintly traceable to the north-northwest, though at a depth of around fifteen centimetres it is barely a crease in the earth now. Elsewhere the defences were cleared, most likely as agriculture intensified and the interior ground was brought into cultivation or grazing.