Two famous Regressive-Pueblo sites in this region, which are known to many tourists, are Puye,[62] on the Pajarito Plateau, and Tyuonyi in El Rito de los Frijoles.[60] Beams from Puye have yielded tree-ring dates ranging from 1507 to 1565. This settlement, perched on a huge mass of yellowish gray tuff, consists of two aggregations of buildings. Forming a quadrangle on top of the mesa, were four, terraced community houses built around a court. There were also houses built in and against the cliff walls, usually at the top of the talus slope. At Tyuoni, whose dates range between about 1423 and 1513, there is a great communal house which was, in part, two stories high and roughly circular in form. It was made of tuff blocks. Three small kivas were built in the center court or plaza. A few hundred yards to the east of the ruin lies a large kiva. For a little over a mile along the canyon wall were cave rooms dug into the cliff and rows of small houses built of tuff blocks. Some of the cave rooms had porchlike structures erected in front of them, but others did not. The largest and strongest pueblo during this period was Pecos, which lay at the headwaters of the Pecos River in northern New Mexico.[73] The first buildings were erected shortly before 1300, and final abandonment did not come until 1838. Such a long record is, of course, of tremendous archaeological importance, and it is indeed fortunate that some of the most extensive and painstaking excavations ever undertaken in the Southwest were at this site. There was evidence of at least six distinct towns. Great masses of pottery have been excavated, with careful attention being paid to stratigraphy, and very detailed studies have been made.[75][77] Well over a thousand skeletons have been obtained and given careful study. [Illustration: Fig. 37—Tyuonyi, Bandelier National Monument, New Mexico. (Courtesy National Park Service.)] Throughout the Rio Grande area, glazed wares were widely made. The earlier forms had glazed designs applied on red vessels. Later, light colored vessels were used. A series of six different types of glazed wares, which were chronologically sequent, have been identified. By 1540 decorations were very carelessly applied and glazed wares were not of a high quality. It was not, however, until the latter part of the seventeenth century that they disappeared altogether and were replaced by light colored vessels, with designs in dull red and black paint, much like those made by the many present-day Indians. [Illustration: Fig. 38—Glazed ware from the Rio Grande area. Regressive-Pueblo period. (Courtesy School of American Research.)]