No stone, no hollow, no outline in the grass. The place is recorded, classified, and mapped, and then it simply isn't there.

What the records classify it as is a sweathouse, known in Irish as a tigh alluis. These small stone structures, typically low-roofed and just large enough to crouch inside, functioned as a kind of rural sauna. A fire would be lit inside to heat the walls, the embers raked out, and a person would enter and sweat for a period before plunging into a nearby stream or lake. They were used as a remedy for rheumatism and other ailments, and they appear across the north and west of Ireland particularly, often close to water. The Ballynary example was situated on a slight rise just above Lough Arrow, which would have made it convenient for the cold-water plunge that completed the treatment. It almost certainly dates to after 1700, placing it in a period when such structures were still in active folk use rather than ancient prehistory. At some point between its construction and the present day, whatever was built there has vanished entirely, absorbed back into the landscape without leaving a trace that fieldwork has been able to recover.