It is a sweathouse, a type of pre-modern Irish structure used much like a sauna: a fire would be lit inside, the embers raked out, and a person would crawl in through the low entrance to sweat out illness or pain. They are found scattered across the Irish countryside, mostly in the northern and western counties, and this one at Rover is a particularly self-contained example, tucked against the land rather than standing free of it.

The structure is circular in plan, with an internal diameter of 1.65 metres and a height of 1.6 metres, which is to say it would be a snug fit for anyone inside. The walls incline slightly inward and are topped with a lintelled roof, the lintels being flat stones laid horizontally across the opening at the top rather than any kind of arch. The entrance, facing east, is just half a metre wide and 0.65 metres tall, so entry would have required stooping low or crawling. A stream runs roughly 75 metres away, and the proximity to water is typical of sweathouses generally, since bathers would plunge into cold water after the heat. A deserted house stands about 20 metres to the north-west, suggesting this corner of the landscape was once more inhabited than it appears today. The sweathouse appears on the 1914 edition of the six-inch Ordnance Survey map but not on later ones, which gives some indication of when it was last considered a feature worth recording.