Mountain Biking

Gravity Assisted Mountain Biking, Av. 16 de Julio 1490 (tel. 0102/2313-849; www.gravitybolivia.com), is by far the best biking outfitter in Bolivia. From La Paz, you can choose from more than nine different 1-day biking trips. The most popular is the 64km (40-mile) descent from La Paz to Coroico along the most dangerous road in the world. The road is narrow, unpaved, crowded with trucks, and carved out of a cliff. Be careful: In 2001, a woman died here when her brakes snapped. Make sure your bike is in good condition. Gravity Assisted Mountain Biking also arranges rides to Sorata and the Zongo Valley. Another company worth checking is Downhill Madness, Sagárnaga no.339 (0102/2391-810; www.downhill-madness.com).