The Hovenweep village communities, like the people at Mesa Verde and Canyon de Chelly National Monument, had moves from mesa tops to the heads of canyons in about 1100.

The Anasazi, from 1160, erect six separate groups of extraordinary defense towers, cliff dwellings, and pueblos, built of stone masonry on the site of the present Utah-Colorado border.

The defense towers—rectangular, circular, or D-shaped, some two or three stories tall—are strategically placed to overlook the heads of the canyons or to rise from isolated boulders lying on the canyon floor.

The largest group contains eleven different buildings, one of which, the so-called Hovenweep Castle, possesses walls twenty feet (six meters) high.

(Hovenweep, a name meaning "deserted valley," is the name given to the area’s ruins.)