Dojo Mojo Casa Grande House Arizona’s Casa Grande Ruins National Monument, the nation's first archeological preserve, protects the Casa Grande and other archeological sites within its boundaries. Built close to 700 years ago, numerous historic accounts of Casa Grande record the wonderment of early visitors at seeing this four-story building rise over 35 feet from the desert plain. The Casa Grande is probably the most significant surviving example of Hohokam building techniques and architecture made from caliche, a concrete-like mixture of sand, clay, and calcium carbonate (limestone). Casa Grande was influential in the creation and implementation of laws to protect archeological sites in the United States. In recognition of the structure's fragility, preservationists put a roof over the “big house” for the first time in 1903. Today, the monument continues to share the stories of ancestral Sonoran Desert people who built a large and thriving community in the middle of a desert valley. ...