This is the entrance to a sweat houses at Dulargy, Ravensdale in north Co Louth.
Sweat houses are believed to have been constructed up until the end of the 19th century.
They were small stone huts with a small entrance. Fires were lit inside the building to heat the stones and after it had died down, the ashes swept out.
People would then enter the house, the door would be sealed, sometimes with the clothes they had taken off, and they would remain there for several hours.
This was believed to be a cure for several ailments.