In addition to doorways, many rooms, especially toward the back or sides of the pueblo and in the lower tiers, had one or two openings about a foot square, high in the back wall. These are above the height of an average man even today, and could not have served as view holes or windows for the Indians. They must have been put there for ventilation. [Illustration: ] [Illustration: Cross section and photograph of an over-under corner doorway.] There are a few other openings in some walls which are not as large as the average doorway or as small as the ventilators. Usually these are placed at a medium height in the room and could well have served as windows to allow a view from one room to another. None of these so-called windows, however, opens to the rear or sides of the pueblo, nor is any known that opens onto the plaza in front. Not counting the Great Kiva, which bulks so large in the plaza, excavations have revealed at least 29 other kivas or ceremonial chambers. Several, especially in the southeast corner, underlie the main structure and may represent kivas from the earlier or Developmental Pueblo Period. Besides the cluster of small kivas around the southeastern corner, there is a second grouping of larger kivas among the rooms in the northeast corner and out into the northeastern part of the plaza, where a rather large Chaco-type kiva is located. A third cluster, composed of smaller Mesa Verde-type keyhole kivas, is located near the southwestern corner of the pueblo, and Morris found scattered remains of one or two other kivas toward the front of the southwestern part. The Great Kiva, or House of the Great Kiva as Morris called it, is centrally located in the south side of the plaza. It is essentially circular in form and has two distinct parts. The inner part—the kiva proper—has a floor about 8 feet below the surface. At ground level, and surrounding this inner section, is an outer circle of 14 arc-shaped rooms. Twelve of these are essentially similar, but the other two are markedly different. One is merely an open passage about 3½ feet wide which leads directly from the plaza to the head of the south stairway. The other is a large rectangular alcovelike structure on the north side of the kiva proper, with a stairway leading up into it from the kiva floor. On the north and west sides of this alcove, there is a low benchlike structure around the inner wall, and on the south side are what appear to be a piece of a wall and two rectangular masonry blocks. Toward the center back portion of the alcove is another low square masonry structure which may have been an altar. When excavated, this latter structure had burned poles embedded in the north side as though it once had a small roof or some kind of entablature over it.