Phoenix is the natural base for exploring central Arizona. Sedona, two hours north, swaps the desert flats for red-rock canyons and a New Age scene that traders sometimes mock and sometimes embrace. Prescott offers a mile-high pine-forest climate and a Wild West main street that still feels alive after dark. Scottsdale, Tempe, and Mesa are part of the same metro and are easily reached by light rail or a short drive; each has its own distinct character.
For prehistory, Casa Grande Ruins preserves the largest Hohokam structure still standing, about an hour south on Interstate 10. Further afield, the Grand Canyon is a long but doable day trip — set out before dawn and you can be on the South Rim by mid-morning, with a few hours to take in the canyon before heading back.