A short easy hike along a gravel path, the Cholla Cactus Garden of Joshua Tree National Park glows in early morning and late afternoon sunlight.  Twenty miles north of the Cottonwood Visitors center, this dense patch of panda bear cholla grow at the base of the Hexie Mountains to the west.  A mile north and south of the trailhead parking lot, drivers are warned not to pull off the road.  At the trail, you quickly see why - tiny heads of cactus dropped off the mature cacti and blown about by the wind.  The hiker is likewise advised not to leave the gravel trail.  Against the dark green Hexie Mountains, the yellow-white needle cloaked cholla look like something out of a fantasy.