Aztec Ruins National Monument
One of the better-preserved centers constructed by the ancestral Pueblo Indians, the Aztec Ruins are an excellent example of Anasazi architecture. Possibly connected to the Chaco Canyon culture, the ruins were abandoned around 1300 CE as the people moved out of the region. Though archaeological work has taken place at the site since 1878, much of the site remains unexcavated. The Aztec Ruins National Monument was declared a UNESCO World Heritage Site in 1987. Easily accessible, the site offers many an opportunity to visit an ancient site that does not require travel to a remote destination.
Backstory and Context
The people who would become known as the Anasazi began to develop a distinctive culture in the four corners region of the American southwest around 1CE. Producing distinctive works of art, architecture, settlement patterns, and agriculture, the culture reached its peak around 1300CE. The culture is known as the Chaco Civilization. Speculation and research toward the abandonment of Anasazi settlements point to climatic changes that lead to reduced agricultural output. Anasazi is a Navajo word that likely means “ancient enemy,” and the name is considered derogatory by modern Pueblos. 
Construction and occupation of the Aztec site appears to have occurred over a 200-year period. Consisting of several large buildings and many smaller ones, The West Ruin is the largest of the excavated buildings. It is made up of over 400 rooms that surround a large plaza. Ruin walls rise to 30 feet in height. A circular structure used for ceremonial purposes named the Great Kiva has been excavated and reconstructed. Excavated items include tools, clothing, jewelry, and pottery. 
European exploration of the area began with the Spanish. An American expedition in 1859 explored the San Juan and Animas River drainage. The expeditionist, Geologist, J.S. Newberry, described a ruin in the Animas River Valley south of the Old Spanish Trail and approximately twenty miles north of the river’s junction with the San Juan. He describes large Pueblos with twenty-five-foot walls and windows fifteen feet above ground level. Newberry noted that yellow sandstone provided the building material and many rooms featured plastered walls. Newberry also indicated that large amounts of broken pottery surrounded the buildings. Newberry described the terraces upon which the ruins were constructed, and the fact that natives continued to visit the site. 
The San Juan and Animas River Valleys were settled in the 1870’s and excavations began in 1878. Lewis Morgan, an anthropologist, developed a floor plan and exposed many rooms.  A report produced by the Department of The Interior identified the Aztec Ruins as being particularly well preserved and as being suitable for government protection.  Excavations by the American Museum of Natural History began in 1916. Archeologist Earl H. Morris worked the site for the next seven years.  President Warren G. Harding established the Aztec National Monument in 1923. The Aztec National Monument covers 319 acres, though only two of fourteen mounds have been excavated. The site was designated a UNESCO World Heritage Site in 1987. A museum is in the visitor’s center and a one-quarter mile-walking trail leads visitors through the grounds.