As with other units of the national park system, Bandelier was created for both conservation and recreation. The primary resources being conserved are cultural (archaeological and anthropological) and scenic (canyon and mesa country, merging into mountain scenery at the upper end of the park). Both follow from Bandelier's setting atop the Pajarito Plateau, a gigantic, ancient (1-2 million year old) ash flow from a volcanic eruption in the nearby Jemez Mountains, that over time has eroded into a network of canyons and mesas. This rugged terrain is responsible for both the scenic beauty of the monument and the capacity of this otherwise arid landscape to maintain an indigenous population that lived along the streams in the canyons, and in some cases, on the mesa tops above them. The early Puebloans have moved on to other locations in northern New Mexico, but the ruins of their habitations and ceremonial structures remain to be protected by the monument.

The monument's headquarters, visitor center, and most accessible features are in Frijoles Canyon, a typical example of the canyons incised in the plateau, but notable for its abundance of ruins. These result from the fact that in contrast to most canyons on the plateau, Frijoles has a stream in its bottom, the Rito de los Frijoles -- Bean Creek -- that runs nearly year-round. (Most canyons have seasonal streams that dry up during parts of the year.) Frijoles Canyon is also fairly wide for much of its length, and the combination of the resulting open spaces and available water allowed the ancestral Puebloans to practice agriculture relatively successfully. Remnants of Puebloan agriculture can still be seen in the canyon, even though the dwellings were abandoned centuries ago.

Many of the ruins in Frijoles Canyon have been excavated, studied and preserved. The main loop trail from the visitor center (see under "See") passes by several types of restored dwellings: communal stone structures along the canyon floor (think of a prehistoric "apartment complex"), "cliff houses" built of stone and mud backed against the canyon wall, and a few "cave dwellings" in holes in the volcanic tuff of the canyon wall. Other archaeological features typical of the Puebloans are the religious structures known as kivas. These are circular, half-buried structures that in Puebloan times would have had flat roofs and entrance ways. Most kivas were perhaps 15 feet (5 meters) in diameter, but many Puebloan villages were built around a "great kiva" that was much larger. An example of a great kiva has been restored in Frijoles Canyon. Today's pueblos along the Rio Grande still use kivas in ceremonies. All of these types of ruins can be found in some of the park's other areas, although most have not been restored; in fact, you may encounter archaeologists on the job at some sites (please don't disturb).

A note on terminology: The term "Anasazi" has frequently been used to describe the Puebloan culture. Recently it has fallen out of favor, as it translates to "ancient enemy" or "enemies of our ancestors". The ancestral Puebloans were labeled "Anasazi" by rival tribes in the area.