Visit Joshua Tree's Best Lookout Point at Sunset
Key's View is the best drive-up vista in Joshua Tree National Park. From the top you can see the Coachella Valley and the San Andreas Fault. You can also catch a view of Southern California's two highest mountains, Mount San Jacinto and Mount Gorgonio. On a clear day you can see California's largest lake, the Salton Sea.
Visit the Mysterious Giant Rock
This is quite literally a giant rock in the desert. According to most sources it's the largest freestanding boulder in the world at about 7 stories high.