I have to admit, Tucson is not one of my favorite cities, but, there are some interesting things to do around there.
They have a zoo. But better yet, they have the Sonoran Desert Museum which is like a zoo with animals indigineous to the desert. They have Old Tucson, which is a movie studio which was used to film a lot of old westerns. Sabino Canyon is very close. If you're interested in history, there is an old mining town, Bisbee, not too far from Tucson. There are vinyards down towards Patagonia. You could check out Kartchner Caverns or Colossal Cave.
You are less than 2 hours away from Phoenix, so you could come up and visit some of our sites. Rawhide is a western town theme tourist place. We have a wonderful zoo and botanical garden.
You are 5-6 hours from San Diego for a quick weekend getaway.