The entrance is by ladder through the hole in the ceiling, which is also the smoke outlet. The floor is paved with slabs of stone, and is about 12 inches higher at the right-hand end. There are places on each side for the looms, blankets being woven in the kivas. The fireplace is the black square. At the left is the plank containing the sacred orifice called the sipapu. The foot of the ladder rests on the edge of the raised portion of the floor ] [Illustration: CHACO RUINS MASONRY From _Report_ of Hayden Expedition; 2 and 3 not found in modern Pueblo architecture ] [Illustration: From Hayden _Report_] There were many round towers of stone in the South-west, also the work of the Pueblos. Some stand alone but most of them are near other ruins. Often they were built with two or three concentric walls from two to five feet apart. A double-walled tower on the Mancos had an outer diameter of forty-three feet. Some of them may have been watch-towers, but those connected with other buildings were perhaps religious structures, or were used somewhat as the kiva[204] is to-day. The kiva is a room now usually square, in part, or wholly, below the general surface of the locality, used as a kind of club-house, council-house, lounging place, and meeting place for members of the society to which it belongs; and also a lodging place for the men; women are generally excluded. In Zuñi, the kivas are rooms on the ground floor. Many ancient kivas were round. [Illustration: RUIN CALLED CASA GRANDE, ARIZONA]