Joshua Tree National Park is of course best known for its eponymous, tree-like plant, a member to the yucca family. However, the park's 800,000 acres are also home to wealth of other flora including Cylindropuntia bigelovii, often referred to as the "teddy bear's cholla" (for its treacherously soft-looking spines). The Cholla Cactus Garden is a dense stand of many hundreds of these highly distinctive plants,together with other natives of the Pinto Basin including creosote, jojoba and calico cactus. The garden can be explored via a 0.25 circular trail.
If you go:
Be sure to heed the many warnings to keep strictly to the trail and not to touch these plants - the spines will transfer to your skin at the slightest touch and are difficult and painful to remove.
Links:

Pinto Basin Road
Joshua Tree National Park, California 92277 USA
Mailing address:
Joshua Tree National Park
74485 National Park Drive
Twentynine Palms, CA 92277-3597 USA
Phone Numbers:
Visitor information
+1 (760) 367-5500
+1 (760) 367-5500