In November 1926, a steam threasher sank into the ground on Rennibister Farm. Once the threasher had been removed from this new hole, an earth-house or souterrain was found, the collapse of the roof being the downfall of the farm machinery.
Inside the structure were found the remains of 19 individuals - the earth-house having been used as a burial vault, presumably after it was no longer used as a cellar by the living!
The modern entrance is through the roof of the main chamber, through which the thresher fell. The original entrance was at the far end of the passage that runs from the chamber.