Say Peru, and you picture Lima, city of kings, birthplace of the New World; or the intricately joined stones of Cuzco; or Machu Picchu, that magical aerie, poised precariously between earth and sky. A regular in the region might picture the rainforest wonder of Manu, that magnificent reserve in the Peruvian Amazon. Or the desert oasis of Paracas, with its brightly colored hummingbirds and rugged sea.

But it takes a veteran of South American travel to picture the Callejon de Huaylas, a verdant corridor between two majestic ranges, a place Peruvian historians call "the cradle of Andean culture." Though I'm a native of Peru who has returned year after year to immerse myself in the world of my ancestors, I'd never traveled to this legendary valley. It took a National Geographic expedition to get me there.

Bobby Haas, a seasoned aerial photographer, was on the seventh leg of a yearlong project to take bird's-eye views of all of Latin America for a lavish volume to be released in September. When, in e-mail correspondence with him, I casually expressed an interest in seeing the mountains of Peru from that vantage, he invited me to go along. Now, I'm no high-risk adventurer and actually prefer the comforts of a good tub to the rigors of the road, but when I learned that that particular leg of Haas' expedition would take in the Callejon de Huaylas, I couldn't help but remember an old Inca dictum that says: When the eagle of the North meets the condor of the South, the spirit of the Earth will awaken.

The spirit of the Earth will awaken! Some old ghost of Peruvian superstition must have come over me, for I was suddenly convinced that I was the condor, Haas the eagle, and this trip was meant to be. I decided right then and there to buy the long underwear and thick boots I would need to brave the glacial temperatures with him.

We boarded a Pilatus Porter — a robust little plane — in a sandlot outside Lima. It was June, the start of a foggy autumn along the Peruvian coast but paradoxically, the very heart of the Andean summer. Our pilot was Swiss-born Rudolf Eberli, who has lived and worked in Peru for 25 years; his co-pilot was a young Peruvian named Manuel Garcia.

Haas strapped himself in with an improvised belt, long enough to allow him to lean out the open door at 20,000 feet and get a good view of the landscape that would unfurl as we flew from the coast inland, over desert and the jagged crests of the cordillera, toward the lush green canopy of the Amazon jungle. At Haas' feet was a bag filled with three mammoth cameras; beside him, Carolina Rosso, a tour guide charged with plotting our course and arranging the paperwork that a complicated multinational expedition entails. I sat behind, wrapped in three coats, warm gloves, strong boots, a balaclava and ski goggles, for the freezing wind through the open door would be hellacious as we flew over the snow-peaked Andes.

AWESOME MOUNTAINS

Our objective was the Cordillera Blanca and the Cordillera Negra, which jut from the earth like the gnarled spines of two mythical creatures. The Cordillera Huayhuash, a compact range of mountains known to hardy climbers, is just south. And nestled between, like a sleeping green serpent, lies the lush valley of the Callejon de Huaylas and its colorful string of mountain towns: Recuay, Huaraz, Carhuaz, Yungay, Caraz.

The Cordillera Blanca boasts the tallest mountain in Peru, Mount Huascaran, whose snow-capped peak at 22,204 feet can be seen up and down the Andean highland and is considered by many the most beautiful in the world. Even veterans of the Alps or the Himalayas cannot help but be awed by this spectacle of snow and sky. The glaciers of the Cordillera Blanca — more than 600 of them — stretch as far as the eye can see. It is here that the continent's rivers begin and the Amazon rainforest is nurtured.

We approached from the iridescent waters of Lake Junin, flying over the Bosque de Piedras, a veritable city of stone formations that thrust toward the clouds — some as high as 20 stories. As we winged over the silver mines of Cerro de Pasco and the trails of the Cordillera Huayhuash, we could see the sunlit promontory of Mount Huascaran beckoning from the distance. We flew into the mouth of the Callejon, swooping low between the two ranges.

The sights from the air are unequaled, but by far the most popular way to explore the Cordillera Blanca and the Cordillera Huayhuash is by foot. Once we landed at Anta, it was evident that earthbound travelers have plenty of reasons to come here.

Rare Andean flowers abound in the mountain soil: gigantic Puya raimondii rise from volcanic rock, their flowering stalks as tall as 30 feet. The waters of the Llanganuco Lakes sparkle a bright turquoise in the distance. At the Rataquenera Scenic Lookout, hikers are rewarded with a panoramic view of Huaraz and its yellow-flowered hills.

Veterans of Andean travel head for Huaraz, where from the comforts of the Swiss-run Hotel Andino or the Hotel El Tumi, they can hike to the gorgeously colored canyon of Pucaventura. The more adventurous will attempt five- to seven-day treks into the icy reaches of Mount Huandoy or Alpamayo.

A GRIM HISTORY

For all the physical beauty that this region offers, however, its residents have known their share of hardship. The geologic activity that created the mountains continues to haunt these ranges. In 1941, Lake Palcacocha flooded the northern half of Huaraz, killing 5,000 people. In 1962, the town of Ranrahirca was obliterated by an avalanche that tumbled from Huascaran. On May 31, 1970, an earthquake registering 7.9 on the Richter scale shook Huaraz, Carhuaz and Yungay to rubble.

Yungay suffered a double catastrophe when, even as its walls were crumbling, an ice-bound lake cracked open and spilled down, bringing a deluge of ice and rock that buried the city in a matter of minutes. The roofs of houses still bristle from the earth, as do the crowns of giant palms that once lined the main square. Dead now, those blackened branches make somber markers for the 70,000 people buried alive in this region.

But the lure of the mountains is strong, and Andeans have long succumbed to it. The first evidence of "el hombre Andino" can be found in the Guitarrero cave, whose wall etchings and primitive implements date to 10,000 B.C. Here, too, is Chavin de Huantar, "umbilical of the world" — a striking architectural ruin of a civilization that thrived from 800 to 200 B.C.

As we flew over that gash of green between the jagged cordilleras, shivering in the sub-zero temperatures of our tiny craft, I couldn't help but note that our eyes were not necessarily drawn to the ancient ruins or the man-made structures that dimpled the valley beneath us. They were on the fuchsia lakes, the rock formations, the windswept dunes, and the way the Andes seemed to ride the blue haze. We were seeing the land not as human beings, but as great-winged birds. And beneath us, the spirit of the earth was awakening.

Marie Arana is editor of The Washington Post Book World section and the author of "American Chica" and "Cellophane."