Papago Park is a hilly desert park covering 1500 acres in Phoenix and Tempe. It’s a great spot for running, featuring a combination of paved and non-paved trails, moderately hilly. There are several interesting sights, including Hole in the Rock, the Desert Botanical Garden, several small lakes, and the Phoenix Zoo. There are numerous trail and loop options. Here is a LINK that describes several routes, including a 3.1-mile gravel ‘fitness trail’. It’s ~2.5 miles N-S and ~1 mile E-W.
The park trails can be combined with runs Arizona State University and the Tempe Town Lake Trails.Information on Park