The enclosure at Garrynamishaun is barely legible now, its defining earthworks reduced to a degraded scarp and an external fosse, the term for a defensive or boundary ditch, that arc from the south-east, sweep through the south, and trail off toward the west-northwest. An outer bank, surviving only in a short stretch of roughly six metres, is just visible at the southern side. Field boundaries have cut across the remains at both ends, compressing whatever the original circuit looked like into a surviving interior space of approximately 35 metres east to west and more than 25 metres north to south.

By the time the third edition of the Ordnance Survey six-inch map was produced in 1945 to 1946, the site was already ghost-like, represented only by a line of hachures, the cartographic shorthand for a slope or earthwork, curving across the hillside before disappearing beneath the field system. Whether the enclosure was a ringfort-type settlement, a stock enclosure, or something else entirely is not recorded; the earthworks are too worn to resolve the question with confidence. What is clear is that the site was substantial enough to be mapped, and old enough to have been largely swallowed by the landscape long before anyone thought to document it systematically. The inventory compiled by Olive Alcock, Kathy de hÓra, and Paul Gosling in 1999 notes it as very poorly preserved, which is a measured way of saying that the hillside has very nearly finished the work that the centuries began.