A circular rath, roughly 34 metres in diameter, has been so thoroughly absorbed into the working farmland around it that its eastern arc has left no visible surface trace at all. What marks it out, quietly and without drama, is a band of darker vegetation curving through the pasture, where the disturbed or enriched soil beneath still influences what grows above.

A rath is an early medieval enclosure, typically of earthen banks, that once defined a farmstead or homestead, probably occupied somewhere between the sixth and twelfth centuries. The Drumharsna example retains its bank of earth and stone along the southern, western, and northern sections of its circuit, but a later field wall cuts straight through the monument at both the northern and southern points, a reminder that these sites were not always recognised or respected as the landscape was reorganised for agriculture in more recent centuries. McCaffrey noted the site in 1952, cataloguing it as number 39 in a local survey, and that record remains one of the few formal acknowledgements of its existence.

For anyone walking the land with an eye for slight irregularities, the partial bank is the thing to look for, low and unspectacular but traceable through the grass on the south and west. The darker vegetative band to the east is easier to read from a slight elevation or in certain light conditions, when the contrast between it and the surrounding pasture becomes more apparent. The field wall bisecting the site is itself an old feature, its presence suggesting that even within living memory the rath was treated simply as part of the farm rather than as a monument separate from it.