In this room, someone designed an innovative air circulation system to allow for an indoor fire. A stone-lined ventilator trench is connected to an opening in the base of the cliff wall.
The upright stone slab at the end of the ventilator trench deflected incoming air so that the draft would pass directly across the firepit. Smoke would exit through a roof opening.
Note how preservation efforts have changed this building: original floor surface, as with this room, are much lower - dirt placed in the rooms after excavation protects floor features and keeps walls from collapsing.
Throughout the dwelling you'll see a variety of modern drains that keep water from standing in rooms. In some cases the architecture has been altered. For example, the square and round holes on this front wall were placed for drainage, and the large masonry column built in the back corner supports the upper wall.
Meghann M. Vance, Northern Arizona University Anthropology Laboratories