The whole interior measures just three metres north to south and two metres east to west, barely enough space for a person to lie down at full stretch. That compactness is part of what makes it curious: this was not a farmstead or a fortification, but something much more minimal, a shelter reduced to its essential geometry.

The structure is built from unmortared stone, with a curving wall reaching about three-quarters of a metre in height along its surviving arc. On its southern side, this curving wall meets a longer east-west stone wall, seven and a half metres in length, which it abuts rather than bonds with, suggesting the two features may have had distinct origins or functions. A narrow entrance, just under a metre wide, faces the south-east. Drystone construction of this kind, fitted without mortar by careful selection and placement of stones, was used across many centuries in Ireland for everything from field boundaries to small enclosures associated with seasonal herding or anchoritic retreat. Without excavation, it is difficult to assign a confident date or purpose to the Mullaghmesha example, and it remains an open question whether it sheltered a person, an animal, or served some other purpose entirely.

The measurements and orientation were recorded through personal communication with J. Kiely and published in the fifth volume of the Archaeological Inventory of County Cork in 2009. Beyond those bare dimensions, the site speaks mostly through what it withholds: a doorway pointing towards the morning sun, walls that have outlasted whatever they once enclosed.