Case Grande ruins, AZ (#38115129)
Stock photo of the ancient ruins remaining at Case Grande Ruins National Monument near Case Grande, Arizona. The â€œBig Houseâ€ is an imposing 4-story building dating from the late Hohokam period, probably 14th century. It is believed that the Casa Grande was a kind of astronomical observatory as the four walls face the points of the compass, and some of the windows are aligned to the positions of the sun and moon at specific times. There are several other ruins in the complex, some of which has not yet been excavated.