WEST TUCSON. The Arizona-Sonora Desert Museum is one of Tucson's star attractions, with good reason. Part zoo, part natural history museum, and part botanical garden, the facility is set on 21 acres and is home to numerous animals that roam freely within invisibly-fenced enclosures. After checking out the exhibits in the main visitor center, wander along two miles of paved pathways, where you can catch sight of endangered species such as the Mexican wolf, thick-billed parrot, ocelot, margay, jaguarundi, and the Gila topminnow; and not-so-endangered critters like leafcutter ants, black bears, river otters, bighorn sheep, coatis, beavers, coyote, javelinas, black-tailed prairie dogs, termites and roadrunners. And don't miss the captivating cactus garden or the Hummingbird Aviary!

WEST TUCSON. It may seem a bit unorthodox these days to center a museum around a collection of stuffed and preserved animals and insects, but this one actually succeeds. Starting with the holdings of numerous educational institutions and individuals, the curators here have developed an engaging, hands-on learning experience. True, the taxidermists' craft is well represented, but where else can kids (and adults) touch and handle real skulls, fur and skin? And unless you see them up close, it's difficult at best to envision the size and mass of a rhino, a grizzly bear or an elephant. And while you've probably seen "Ice Age" at least once, there are only a handful of places to see a real saber-tooth cat, and this is one of them! Those are some mighty long fangs...

DOWNTOWN. Here you'll find research facilities for two divisions of the National Optical Astronomy Observatories. Located on an 80-acre mountaintop leased from the Tohono O'odam tribe for 200 years, the facility is 80 miles west of Tucson, but for those interested in astronomy, the top-of-the-line telescopes and exhibits are a must. Knowledgeable staff members can help you get a closer look at the mysteries of the universe. Reservations are required to participate in the nighttime observatory tour.

AIRPORT. Aviation buffs, this one's for you. The Museum opened to the public in May, 1976, with 75 aircraft on display. Since then the collection has grown to over 250 aircraft occupying 80 acres of land. The entire museum property covers about 150 acres. One plane of interest is the Lockheed Tristar, used by John Kennedy as Air Force One on short flights or flights to small airports. This museum also operates the Titan Missile Museum. Package admissions to both sites are available.

NORTH TUCSON. Although the T Rex Museum definitely strives to entertain and educate the under-12 set, there are plenty of adults who will find it engaging. The private museum is packed with cool stuff ­ fossils, dino replicas, displays of live insects and reptiles (for perspective), hands-on exhibits, and activities. At the end, venture in to the Paleo Pits where you get to dig for (and keep!) your very own dinosaur fossil. If you have kids, don't miss this one!