Mesa is a city in Maricopa County, in the State of Arizona and is a suburb located about 20 miles east of Phoenix. Mesa is the central city of the East Valley section of the Phoenix Metropolitan Area. Wikipedia

Tucson is a city in and the county seat of Pima County, Arizona, United States, and home to the University of Arizona. The 2010 United States Census puts the city's population at 520,116, while the 2013 estimated population of the entire Tucson metropolitan area was 996,544. Wikipedia