Canyon de Chelly National Monument, area of rock formations and archaeological sites in northeastern Arizona, U.S., on the Navajo reservation immediately east of Chinle. The name is a Spanish corruption of tsegi, a Navajo word meaning “rock canyons.” The monument, which was established in 1931, occupies 131 square miles (339 square km).
It comprises two main canyons—Canyon de Chelly to the south and Canyon del Nuerto to the north—which join at the monument’s western end. Numerous side canyons lead from the main ones. Lining these canyons are several hundred pre-Columbian cliff dwellings, built at the base of red sandstone cliffs or in caves on the steep canyon walls. They cover a longer period than any other ruins in the Southwest, dating between 350 and 1300 ce. Relics of the Basket Maker culture have been found under those of the later Cliff Dweller and Pueblo cultures. Modern Navajo homes and farms occupy the canyon bottoms.