Why were they built on the rocks? Why were they built in a variety of shapes – squares, ovals, circles, and D-shaped? What was the purpose of the buildings? What happened to their builders?
According to literature from the National Park Service:
The towers of Hovenweep were built by ancestral Puebloans, a sedentary farming culture that occupied the Four Corners area from about A.D. 500 to A.D. 1300. Similarities in architecture, masonry and pottery styles indicate that the inhabitants of Hovenweep were closely associated with groups living at Mesa Verde and other nearby sites.The Square Tower Group, located in and around Little Ruin Canyon, which is a short walk from the visitors center, has the largest collection of ancestral Puebloan structures at Hovenweep. The remains of nearly thirty kivas have been discovered as well as a variety of other structures. They think that it is possible that as many as 500 people occupied the Square Tower area between A.D. 1200 and 1300.
The ancestral Puebloans prepared their land for cultivation much like farmers do today. They created terraces on hillsides, formed catch basins to hold storm run-off, and built check dams to retain topsoil that would otherwise wash away. Storage granaries under the canyon rims protected harvests of corn, beans and squash for later use.
Many theories attempt to explain the use of the buildings at Hovenweep. The striking towers might have been celestial observatories, defensive structures, storage facilities, civil buildings, homes or any combination of the above. While archeologists have found that most towers were associated with kivas (Puebloan ceremonial structures), their actual function remains a mystery.
By the end of the 13th century, it appears a prolonged drought, possibly combined with resource depletion, factionalism and warfare, forced the inhabitants of Hovenweep to depart. Though the reason is unclear, ancestral Puebloans throughout the area migrated south to the Rio Grande Valley in New Mexico and the Little Colorado River Basin in Arizona. Today's Pueblo, Zuni and Hopi people are descendants of this culture.
These are the same two buildings in the previous photo, taken from a slightly different angle. Using the zoom distorts and compresses the view somewhat.
Hovenweep House, the largest structure in the area, along with several outbuildings. As seen from the south side of the canyon.
Ruins Canyon, looking east. The two towers are just below the rim of the canyon near the center of the picture. Several other structures dot the landscape, almost blending in with the boulders.
Photographs taken on May 19, 2010.