A sweathouse, known in Irish as a tigh alluis, was a small stone-built structure used for therapeutic sweating, broadly analogous to a sauna. The user would heat the interior with burning turf, clear out the embers, and then crawl inside to sweat for a period before plunging into a nearby stream or lough. They were once relatively common across Ulster and Connacht, modest dome-shaped chambers that have often been mistaken for souterrains or collapsed clocháns. The one that stood at Corratawy was recorded on the Ordnance Survey maps of both 1836 and 1876, which means it survived into the Victorian era as a recognisable and mappable feature of the landscape.

Sometime in the early twentieth century, however, local people dismantled it. The stones were not wasted; they were absorbed into the field boundaries nearby, which is a very ordinary fate for a very old structure. It is the kind of quiet erasure that happens when a community no longer has use for a thing but still has use for its materials. The site lies roughly 180 metres north-east of Drumhurrin Lough, and today there are no visible remains at ground level. The sweathouse exists now only in the cartographic record, a small symbol on two nineteenth-century maps, and in the local memory that confirmed its end.