Casa Grande Ruins National Monument is within the city limits of Coolidge off State Route 87/287. The Casa Grande (Big House) was built by prehistoric peoples called Hohokam prior to 1350 A.D. Partially ruined, the four-story structure is constructed of layers of caliche mud and represents the height of Hohokam architecture. Around the main building are the remains of a walled village; vestiges of other prehistoric villages are nearby.
The Hohokam lived in the area for many centuries prior to the construction of the Casa Grande. Some time around about 1450, Casa Grande was abandoned for unknown reasons after the Hohokam had used it for only a century. The ruins were first seen and named in 1694 by Father Eusebio Francisco Kino, a missionary who was led to the site by local Pima Indians.
The visitor center features a museum. Self-guiding tours and picnic facilities are available.