It does not appear on any Ordnance Survey map before 1914, and the structure itself predates that record by an unknown span of time. It is a sweathouse, a type of early Irish sauna used for therapeutic purposes, typically by heating the interior with burning turf or wood, clearing the embers, and then having the bather endure the residual heat before plunging into a nearby stream or pool. The proximity of running water here is not incidental.

The chamber is D-shaped in plan, built from stone with slightly inclined walls and a lintelled roof, meaning flat stones laid horizontally across the top rather than a true arch. Its internal dimensions are modest even by the standards of these structures: roughly 1.55 metres from east-southeast to west-northwest, between 1.1 and 1.4 metres across, and standing 1.65 metres high inside. The entrance, positioned at the west-northwest, is narrower still, just 0.45 metres wide and 0.55 metres high, which would have helped retain heat once the bather was inside. A house stood approximately 30 metres to the southeast, suggesting the sweathouse was attached to a working farmstead rather than any communal or ritual site. Sweathouses of this kind are found across Ulster and Connacht in particular, and were still in occasional use into the nineteenth century as folk remedies for rheumatism and other ailments.