Rooms in Chaco-Canyon structures were relatively large and high ceilinged, with plastered walls. The inner rooms, which lacked light and air, were used for storage. Household activities were not confined to the rooms, for the roofs of the lower tiers provided additional living space, and much work, such as the preparing of food, the making of pottery, and the flaking of arrowheads, probably took place in the open. Fire places are rare in the rooms, and it seems likely that much of the cooking was done outside—in the courts and on the roofs. At first there were doorways and high windows in the outer wall, but these were later blocked off with masonry. The single gateway in the front of the pueblo was first greatly narrowed and then entirely closed, so that the great house could be entered only by means of a ladder which, if necessary, could be withdrawn. This is some of the best evidence of the fear of attack which must have existed. [Illustration: Fig. 30—Chaco black-on-white pottery of the Great-Pueblo period. (Courtesy The American Museum of Natural History; Taylor Museum photograph.)] In its own way, pottery reached as high a point of development as did architecture. The main wares were black-on-white and corrugated. The former was thin and hard, usually a good white, but sometimes a light gray. Designs were, for the most part, hatchured patterns with the thin filling lines surrounded by heavier boundary lines. Band decorations were widely used. Bowls, pitchers, and ladles were the most usual shapes, but cylindrical vases and effigy pots with human figures were not unknown. The cooking ware was corrugated and usually consisted of large jars with wide mouths. This pottery was very well made, with attractive patterns produced by making sharp, clear-cut, indentations in the corrugations. Some red pottery has also been found. Neither the architecture nor the pottery which we refer to as being of the Chaco-Canyon type was limited to the narrow confines of the canyon itself. They are also represented in such places as the great ruin at Aztec, New Mexico,[94] and at various other sites in the San Juan area. In some cases, particularly in northeastern Arizona, architecture was Chacoan in character, but pottery was not.