There were but 10 rooms on the ground, in addition to one circular kiva; some of these rooms are too small for habitation, and one of them appears to have been a rectangular kiva. On the same bench, about 100 feet westward, however, there are traces of other rooms, the walls of which were very thin. The cliffs back of the ruin and for 200 feet west of it are covered with pictographs in white and colors. [Illustration: Fig. 19--Ground plan of a ruin on a ledge.] Near the center of that portion of the ruin shown on the ground plan there is a large room which may have been a rectangular kiva. The walls are over 2 feet thick in the first story, diminishing at the roof level by a step or setback to the ordinary thickness of about a foot. These walls, as usual in such structures, were about 2 feet thick; they are slightly curved, the front wall markedly so, and the interior corners are well rounded. No reason for this curvature is apparent, and it is certainly not dictated by the occurrence of the rock over which the wall is built, as only the point of this rock comes through the wall in the western side of the front wall. There may have been an opening into the room through the eastern wall connecting it with the room on that side, as the masonry is there broken down; but this is doubtful, as the eastern room itself has no exterior opening. It is more probable that the large room was entered through the roof, for the thin wall of the second story shows in front one side of a well-finished doorway. Just outside of the heavy front wall there is a round hole in the ground, the remains of a vertical shaft connected with the interior of the room. The hole is about a foot in diameter, and is neatly plastered inside, and appears to have been a chimney or a chimney-like structure such as occur in connection with the kivas in other ruins. It will later be discussed in detail. The circular kiva occupies the western end of that part of the room shown in the plan. It was 15 feet in diameter, and is exceptionally well built. The wall is standing for about half of its circumference, and was so neatly finished that the interior coating of plaster was apparently omitted. There are no traces of inclosing rectangular walls; the thickness of the kiva walls and the exceptionally large stones used in parts of it suggest that the kiva stood alone. So far as the walls remain standing, an interior bench can be traced, about 2 feet wide and 6 feet below the top of the outside wall. On the southeastern side, in the interior, there is a buttress or projection, which terminates the bench at this point. [Illustration: Fig. 20--Ground plan of ruin No. 31, Canyon de Chelly.]