Don't go looking for Casa Grande, the national monument of pre-Columbian ruins, in Casa Grande, the sprawling exurb of a town about halfway between Phoenix and Tucson. You have to drive about 20 miles away to the small town of Coolidge to find the site. This may not be the most scenic stretch of desert, it must be said, but the destination is worth the detour.
The Hohokam culture built this complex of dwellings and irrigation canals—one of many—late in their tenure here. Erected in the 1300s, this particular site was abandoned by the mid-1400s—the end of perhaps a thousand years of irrigated agriculture in the Sonoran Desert. The network of villages and canals continue to fascinate archaeologists and urban planners.
The "big house" (Casa Grande was named by the first Spanish explorers in the area) stands about four stories tall. In the 1930s, the current shelter was built to protect it from further erosion. (Look carefully: you might catch a glimpse of the resident horned owls.) The timbers needed for construction came from the mountains about 50 miles away; at the time there were no pack animals, and thus no wheeled vehicles in this desert—makes you think... The surrounding ballgame-courts show influence from Mesoamerica.
Desert civilization in North America is often thought of as a recent phenomenon—take the 20th-century explosions of Las Vegas, Phoenix, etc. Dig deeper, and get off the interstate. The past is not remote, and this is an easy day trip from Tucson.