In addition to sites which were occupied by people with a Chacoan culture and those inhabited by people with Mesa Verde affiliations, there are others which show both influences at different periods. Lowry Ruin,[81] not far from Mesa Verde in southwestern Colorado, contains a Pueblo and a Great Kiva with Chacoan Masonry. The early pottery was not entirely like that found in sites in the Chaco Canyon itself, but closely resembled it. It must be emphasized that _Chacoan_ is simply a term which refers to a generalized culture, and not just to the sites of the type locality. In the top portion of the fill of some rooms at Lowry Ruin is found Mesa Verde black-on-white pottery. It is not known whether this indicates the presence of Mesa Verde people, or if only the pottery, or perhaps even the technique, was introduced. We do know, however, that Lowry Pueblo was occupied, abandoned, and then reoccupied a number of times from the time when it was first built, late in the eleventh century, until it was finally deserted, about the middle of the twelfth century. This is one of the sites which does much to upset certain theories as to the causes of the abandonment of the northern frontier. It was not prepared for defense, and had entrances on the ground level, and there is no indication of any violence. Final abandonment came long before the great drought of 1276 to 1299. An even more famous site is that of Aztec,[94] now a National Monument, which lies one mile north of the town of Aztec, New Mexico. Here were built a big communal house and Great Kiva with Chacoan masonry. The ground plans were almost identical with those of Chettro Kettle, one of the important structures of Chaco Canyon. The main building was in the shape of a square “U”, with an arc-shaped row of rooms in front. More famous than the Pueblo itself is the “House of the Great Kiva.” This remarkable structure was essentially circular, and consisted of a large kiva surrounded by a concentric ring of arc-shaped surface-rooms. The kiva, which was encircled by two benches or shelves, was forty-one feet across at floor level and forty-eight feet in diameter at the level of the second bench. In the floor were two large, masonry-lined, sub-floor vaults and a masonry box, midway between the south ends of the vaults, which is believed to have been a fire altar. The twelve rooms surrounding the kiva are not stained and littered, as are the usual living quarters, so it seems certain that they were strictly ceremonial chambers. On the south side is an alcove, opening directly into the kiva, which is thought to have been a shrine room. A rectangle of masonry in the center of the alcove was presumably a permanent altar. [Illustration: Fig. 33—Betatakin, Navajo National Monument, Arizona. (Courtesy National Park Service.)]