Saguaro National Park is home to the country’s largest cactus, the saguaro, which can grow to more than 40 feet tall. This park has two districts, East and West, which sit on either side of Tucson. The West side, also known as the Tucson Mountain District, is the more popular of the two, due largely to its greater density of tree-like cacti.

The beauty of the Sonoran Desert is on full display at the Arizona-Sonora Desert Museum in Tucson. This 98-acre outdoor museum is home to native animal species like river otters, javelinas, and Mexican gray wolves. Stroll the Cactus Garden for dozens of cactus varieties, including cholla, prickly pear, and organ pipe cactus. On warm days, children can play in the air-conditioned Packrat Playhouse, an award-winning indoor play space with slides and climbing structures.

The Pima Air & Space Museum in Tucson is one of the largest non-government funded aviation museums in the world. Nearly 400 aircraft of all sizes are on display, both inside large hangars and outside on the massive air field. Stroll or take a tram tour across the 80-acre grounds to ogle retired military cargo planes, commercial aircraft, and even presidential airplanes. Several planes on display in the air field have been turned into contemporary works of art as part of the Boneyard Project.

The East district of Saguaro National Park is replete with cactus, though there are fewer to see on this side of the park. The Rincon Mountain Visitor Center is a good starting point ahead of a drive along the 5-mile Cactus Forest Drive, a scenic loop that affords plentiful views of saguaros. Easy trails include the Desert Ecology Trail and Freeman Homestead Trail, both of which use placards to educate on the wonders of the Sonoran Desert—note that Cactus Forest Drive is one-way.

Colossal Cave Mountain Park in nearby Vail, Arizona, is a natural wonder that’s home to one of the largest dry caves in the U.S. The cave system has 3.5 miles of mapped passages. Tours guide visitors along a half-mile stretch to view unique formations, like stalactites and stalagmites. There’s more to see beyond underground caverns, too. The park offers opportunities for hiking, biking, horseback riding, and camping. An on-site café sells craft beers, wines, and snacks.

For more caves, look to Kartchner Caverns State Park in Benson, Arizona. Several cavern tours set off daily (reservations are encouraged), including a helmet and headlamp tour that allows visitors to experience the cave as explorers did in 1974. On terra firma, hike trails, stroll in the Hummingbird Garden, and view native wildlife, like tortoises, lizards, and cottontail rabbits. Kids ages 6 to 12 years old can complete an activity booklet to become a Junior Ranger.

Less than 30 minutes off I-10 is the Old Western town of Tombstone, Arizona, which brims with gunslinging history. Officially the Tombstone National Historic District, there’s a lot to learn about the Wild West across this three-block town. Go underground to explore the Good Enough Silver Mine, take a self-guided tour of the Boothill Graveyard, and visit the O.K. Corral. On Allen Street, dramatic gunfight reenactments take place several times each day.

Bowlin’s The Thing Travel Center (aka The Thing Museum) is a quirky roadside attraction in Benson, Arizona, advertised by dozens of signs up and down I-10 between El Paso, Texas, and Tucson. For an entry fee of $5, you’ll leave with a headful of conspiracy theories that revolve around alien life forms. Without giving away too much, you may learn that aliens allegedly had a hand in everything from the extinction of dinosaurs to World War II. It’s worth a walk through, if only to see “The Thing.”

Located in Wilcox in Southeast Arizona, Chiricahua National Monument has been called the “Wonderland of Rocks.” It’s so magnificent that federal legislation has been introduced to grant it national park status; if it passes, Chiricahua would become Arizona’s fourth national park. The park has hiking trails that range from easy nature walks to strenuous multi-mile hikes. A scenic drive takes visitors to the historic Faraway Ranch and up to stunning vistas at Massai Point.