Tucson, Yuma, and Mesa are all cities in Arizona. Tucson is the largest city in Arizona, with a population of over 500, 000 people. Yuma is located in the southwestern corner of the state, and is known for its hot desert climate. Mesa is located in the east-central part of the state, and is the third-largest city in Arizona. All three cities are popular tourist destinations, offering a variety of attractions and activities.