Two of the estufas in the Cliff Palace deviate from the normal type. This is the only instance where I have observed estufas differing in construction from the ordinary form described in Chapter III. The northern estufa (44 in the plan) is the better preserved of the two. To a height of 1 meter from the floor it is square in form (3×3 m.) with rounded corners (see figs. 35 and 36). Above it is wider and bounded by the walls of the surrounding rooms, a ledge (_b_, _b_) of irregular shape being thus formed a few feet from the floor. In two of the rounded corners on a level with this ledge (a little to the right in fig. 36) niches or hollows (_d_, _d_; breadth 48 cm., depth 45 cm.) have been constructed, and between them, at the middle of the south-east wall, a narrow passage (breadth 40 cm.), open at the top. At the bottom of one side of this passage a continuation thereof was found, corresponding probably to the tunnel in estufas of the ordinary type. At the north corner of the room the wall is broken by three small niches (_e_, _e_, _e_) quite close together, each of them occupying a space about equal to that left by the removal of two stones from the wall. The sandstone blocks of which the walls are built are carefully hewn, as in the ordinary cylindrical estufas. Whether the usual hearth, in form of a basin, and the wall beside it, had been constructed here I was unfortunately unable to determine, more than half of the room being filled with rubbish. I give the name of estufas to these square rooms with rounded corners, built as described above, because they are furnished with the passage characteristic of the round estufas in the cliff-dwellings. Perhaps they mark the transition to the rectangular estufa of the Moki Indians. Besides the estufas there are some other round rooms or towers (21 _a_, 23, 63), which evidently belonged to the fortifications of the village. They differ from the estufas in the absence of the characteristic passage and also of the six niches. Furthermore, they often contain several stories, and in every respect but the form resemble the rectangular rooms. The long wall just mentioned, built on a narrow ledge above the other ruins, and visible at the top of Pl. XIII was probably another part of the village fortifications. The ledge is situated so near the roof of the cave that the wall, though quite low, touches the latter, and the only way of advancing behind it is to creep on hands and knees.