Joshua Tree National Park
I went with a group to Joshua Tree, where we did two somewhat long trails. We started off doing the Lost Palms Oasis Trail, which is in the southeastern portion of the park. It's a nice trail that leads down to one of Joshua Tree's oases, where there's a group of fan palms. Beautiful scenery both on the trail and at the oasis.
Afterwards, we decided to do a bit of off-trail hiking and did a loop in the northwestern portion of the park that's kind of a trail but not really. It was extraordinarily remote, and without GPS we probably would've gotten rather lost. But, it also let us see some gorgeous sites and to see Joshua Tree during sunset.
We also managed to see some wildflowers on the way, and stopped at the Chollo Cactus Garden. All in all, an amazing trip.