At the end of a dirt road in South Mountain's Pima Canyon Entrance, tucked away in a quiet desert arroyo full of mesquite and cactus, you'll find a collection of boulders with names. These are the gems of South Mountain bouldering, a type of low-vertical climbing activity that usually involves rock shoes and a chalk bag but no rope. On nice days, you're likely to find climbers scampering around the Entrance, Africa and World boulders, or the "Amphitheater."The routes here are mostly "clean," which in climber-speak means that the hand- and footholds aren't too likely to break off. South Mountain rock is notorious for coming apart, though, so be forewarned. This isn't Hueco Tanks or Red Rocks. But this area, reportedly developed by locals in the mid-1990s, does offer dozens of established routes, ranging from easy (VO) to ridiculously tough (V7). Basic route descriptions can be found in a popular pamphlet published by local climber Marty Karabin. When not crumbling, the rock here has a smooth yet textured feel that doesn't rip apart the skin as easily as the razor-rock of the popular Queen Creek bouldering area two hours east of Phoenix. Plus, the wash inhabited by the boulders can be a wonderfully peaceful and beautiful hangout — if you don't mind sharing it with the occasional rattlesnake.