America’s Southwest is full of breathtaking canyons, but none as famous or as widely visited as the Grand Canyon. This world-famous landmark offers wondrous views, spectacular hiking, exhilirating whitewater rafting, and countless adventures. One look across the enormous chasm confirms just why this inspirational place is one of the seven natural wonders of the world and a must-see destination for so many travelers. The park also protects a wealth of biological diversity, including numerous endemic and threatened species and several rare ecosystems.

Petrified Forest is best known for its ancient trees that have crystallized over 225 million years into rainbow colors. The park also features fossils from huge 18-foot crocodile-like creatures known as Phytosaurs, as well as remnants from 13,000 years of human history, including the remains of villages, tools, and grinding stones. A 28-mile road runs through the park, offering a number of short hiking trails into the diverse landscape of wild grasslands and Painted Desert vistas and colorful badlands.

It’s the iconic image of the American Southwest: The giant saguaro cactus, standing tall amid the arid desert, arms perpetually raised to the sky. At Saguaro National Park, you can see more than 1.6 million of these giant saguaro—the largest forest of its kind on the planet. The park is divided into two separate and distinct units on either side of Tucson. The Tucson Mountain District to the west of the city features desert grasslands, desert shrubs, and a variety of wildlife; the Rincon Mountain District to the east offers higher elevation vistas and conifer forests climbing the hillsides.

This area was once home to the prehistoric Salado people, named in the early 20th century after the life-giving Rio Salado, or Salt River. The Tonto National Monument protects the ruins of two cliff dwellings that are nearly 700 years old. The park also shares artifacts and stories from this region of the Sonoran desert overlooking the Tonto Basin in southeastern Arizona.