Room 11, which may be called the square tower, is the only four-story building standing in Cliff Palace, its walls reaching from the floor to the roof of the cave. When work began on this building the whole northwestern angle had fallen, and the remaining walls were tottering. To prevent total destruction, the entire corner was built up from a foundation laid on the floor level of the neighboring kiva. A small entrance to the ground floor, or the lowest of the four rooms, is from a banquette (10) on the western side, where there is a passageway from this lower story of room 11 to room 12, situated in its rear. Room 12 has a good floor, and room 11 a fireplace in the southwestern corner of the lowest room of the square tower. Almost all the beams of the higher rooms of this tower had been taken out, leaving nothing but the holes in the walls to indicate the former existence of floors. The beams now connecting the walls were placed there by our workmen to serve as staging and for tying the sides together. The second and third stories of the square tower are also without floors. Their inner walls are plastered a reddish color, in places whitewashed, and the third wall is decorated with interesting paintings. In the western wall of the second story was a small window, and portions of a large T-shaped doorway still show on the northern wall of the third story. Split sticks support the section of wall from the top of this doorway to the roof of the cave. From the arrangement of its rear walls it would appear that the whole of this tower was built subsequently to the rooms back of it, which extend on each side, north and south. The repair of a doorway of the northern wall was difficult, the foundation walls of the eastern and northern corners of the tower being slabs of stone set on edge, quite inadequate to support the lofty wall above. This insufficient foundation leads to the belief that when the base of the square tower was constructed there was no thought of erecting upon it the four stories that we now find. (Pl. 12, 13_a_, 14_a_.) Some of the rooms of the square tower bear evidence of having been living rooms, and possibly the approaches to the upper chambers were by ladders from the outside; otherwise the T-shaped doorway on the northern side, above the painted room, remains unexplained. Room 12, situated east of the square tower, has no characteristic features, being more a passageway than a room, opening at one end into room 13 and connecting with kiva D at the other end. Room 13 likewise presents no distinctive features; its rear wall is considerably blackened by smoke, and it has a large square window opening into room 12.