Joshua Tree National Park
Jumbo Rocks Campground. Big rocks, cool stars, epic sunsets.
Cholla Cactus Garden. Come @sunrise to see the cacti wake up and start their day.
'splorin.
Sunset and the night sky. Too hot to do anything during the day, wait for the sun to start setting and set up your tripod to watch the stars.
Pinnacles National Park
Condor Gulch Trail to High Peaks Loop Trail. Start before everyone wakes up, you'll save yourself from dehydration.