These "Tent Rocks" are located in the Kasha-Katuwe National Monument, in New Mexico. A product of volcanic eruptions dating back 7 million years, these rocks have boulder caps that protect them - those that lose the caps, begin to disintegrate.
There are also canyons and caves in the area, within a relatively short hike from where you park your car. As elevation is much higher there than in Los Angeles, it was more challenging to hike, even though it was not a difficult trail.
And no, you cannot climb on the rocks... so please don't, because we do not need to begin destroying these magnificent formations for the sake of selfies.