Joshua Tree National Park
The 1,200-square-mile Joshua Tree National Park, within the Colorado and Mojave Deserts, has hiking and walking trails, mountain biking paths, and thousands of climbing routes, most of them filled with freestanding granite boulders. This is truly a natural American wonderland. Visit the Oasis of Mara, a lush pocket in the midst of the beautiful arid desert, which in the springtime is surprisingly verdant with plantlife and wildflowers. For something more physically challenging, hike Mount Ryan, which at 5,456 feet is the second highest point in the park. You'll be rewarded with sweeping views of the expansive desert spreading out before you.