Rugged Peru is synonymous with the bold peaks of the Andes, and those mountains, particularly the spectacular Cordillera Blanca range 400km (250 miles) northeast of Lima, are a magnet for thousands of mountaineers and adventure-sports travelers every year. The string of dramatic snowcapped 5,000m (16,400-ft.) peaks east of the Callejón de Huaylas Valley, accessible from the main tourist hub of Huaraz (reached by bus in 7-8 hr. from Lima), is the premier spot in Peru -- and perhaps the best in all of South America -- for climbing and trekking. Nearly three dozen peaks soar to more than 6,000m (19,680 ft.); Huascarán, topping out at 6,768m (22,205 ft.), is Peru's highest mountain and the highest tropical mountain in the world. Nearly the entire chain is contained within the protected Huascarán National Park, a UNESCO Biosphere Reserve and World Heritage Trust site.

Not surprisingly, the region appeals above all to experienced, veteran mountaineers and adventurers. A burgeoning lineup of other adventure sports, from white-water rafting and mountain biking to hang gliding and rock climbing, have lifted off in popularity in recent years. Above all, those kinds of adventure travelers, equipped and prepared for the rigors and thrill of roughing it outdoors, get the most out of the region.

The extraordinary mountain scenery of the region, however, also appeals to those with limited time and abilities, or only passing interest in testing their physical mettle in Peru. The valley, some 20km (12 miles) wide and 180km (112 miles) long, is a superb destination for those who are more interested in day walks and village markets, too. For those who would say all play and no culture makes for a dull adventure, visitors can marry interests in adventure sports and antiquity at the marvelous ruins of Chavín de Huántar, built about 1,500 years ago, a hearty journey about 4 hours from Huaraz. However, getting to the Cordillera Blanca still requires a considerable investment of time, even though one Peruvian airline has finally begun to fly from Lima to Huaraz. Other outdoors areas in Peru (such as the Sacred Valley between Cusco and Machu Picchu, and the Colca Canyon beyond Arequipa) are easier to get to for most light adventurers.

The best months for climbing are the dry season, between May and October; of those, July and August are perhaps best. (Note that the traditional dry season has shifted a bit in recent years, with rains often lasting until the end of May but often not beginning until late November.) Mountain biking and trekking can be practiced other months as well, but the adventurous should be duly prepared for rain.

The small and bustling, ramshackle mountain city of Huaraz has few attractions besides its spectacular setting, but it serves as the base for most adventure-tour operators. With its roster of restaurants, bars, and small hotels, it's where most travelers gather to get acclimated to the altitude and get organized for their forays into the mountains. Besides Huaraz, several other small towns and villages at the base of the Cordillera mountains serve as starting points for trekking and climbing expeditions, but none is so well equipped as the capital of the Ancash department. Many expeditions to the scenic Llanganuco lakes in the Huascarán National Park begin at Yungay, while Caraz, a pleasant small mountain town known for its agreeable climate and flowers, serves as a quieter alternative to Huaraz and offers similar services required for ascents and other adventure activities.

"La" Huascarán? -- The Cordillera Blanca's El Huascarán, the namesake of the mountainous National Park in Peru's central Andes, might seem to be an eminently macho mountain: At 6,768m (22,205 ft.), it's the highest peak in Peru, the fourth highest in the Americas, and the highest tropical-zone mountain in the world. But its north peak was first climbed in 1908 by a woman, the 58-year-old American Annie Smith Peck (who 3 years later climbed Peru's Mt. Coropuna, where she proudly displayed a women's suffrage banner that read "Votes for Women").

Acute Mountain Sickness -- The usual warnings about altitude in the Peruvian Andes especially apply in Huaraz and the Cordillera Blanca. Headaches and nausea are common ailments. Take several days to adequately acclimatize to the high elevation of more than 3,000m (9,840 ft.), or up to a week if you're planning to attempt a serious ascent. In the early going, don't overextend yourself physically, and drink plenty of mate de coca (coca-leaf tea). If symptoms persist, see a doctor. Acute mountain sickness, known locally as soroche, is serious business.