The remains of pit-dwellings are the remains of a structure in which the ground was dug down to create a floor, a post hole to support the roof, and a furnace for light, warmth and cooking. Of these, a pit-dwelling longer than 10 meters in length is called large pit dwellings.
The remains of pillar-supported (hottate-bashira) structures were constructed by digging a hole in the ground and erecting pillars 50 to 70 centimeters in diameter to support the floor and roof. Of these, a pillar longer than one meter in diameter is called large pillar-supported structure.
