On the crest of a bold cliff-hugging dirt road 8,000 feet high in the Peruvian Andes Mountains, I saw the pagan altars and grand plazas, roofless stone homes and twisting stairwells of the magnificent Incan ruin, Machu Picchu.

Once a bustling mountaintop community that was inexplicably abandoned in the 16th century, Machu Picchu rested alone for almost 400 years. But today, it reawakens with each visitor.

Pure white clouds hang over the city of stone like a canopy. And below, only the distant rush of the Urubamba River breaks the soft silence.

Llamas, the Andean beast of burden that helped carry the stones to build this citadel, graze on the terraced slopes surrounding the ridge. White potatos and giant corn grow there too, fed by the fresh mountain streams channeled through Incan aqueducts.

As the glass-top tourist bus rounded the last winding turn toward Machu Picchu, I joined two dozen other foreign travelers stepping into a city of narrow passageways and tiny conclaves. Walking through the ancient community, we touched long-ago genius: Stone walls so perfectly niched that without a smidgen of mortar they have outlasted centuries. A sundial so accurate that the bus driver keeps his schedule by it. A grand plaza so well preserved that except for the mummies that were once wrapped there, it remains intricately intact.

Until 1911, when Yale professor Hiram Bingham, in search of another Indian ruin, rediscovered Machu Picchu, it was the secret of the Incas who dominated the culture of northwestern South America from the 12th century until the 16th-century Spanish conquest.

"You're walking through the Lost City of the Incas," I told myself, yet arriving there was half the adventure.

From Lima, the Peruvian political capital on the Pacific Coast, travelers fly 350 miles southwest to Cuzco, the Peruvian tourist capital. From there, the nearest city to Machu Picchu, a three-hour train ride through a wet river valley and a 20-minute climbing bus ride bring you to the brink of the 12th century.

Lima is where nearly all international flights land, but you probably won't want to delay long there.

Though historical, much of Lima's Spanish colonial architecture and floral parks have been marred by haphazard urban sprawl. Deteriorating homes, relentless traffic and 5 million people, a great many of whom seem to be selling something, clog the capital.

Walking toward Lima's focal point, the Plaza de Armas, you see hundreds of street merchants. If you don't feel like buying or bargaining, avoid eye contact with them. Otherwise you'll find -- as we did -- a mob surrounding you offering hand-woven belts and Indian pottery.

Normally a loud, cluttered square where impatient drivers honk and homeless people congregate, the Plaza de Armas calms at noon. Then, during the brief changing of the guard ceremony in front of the Government Palace -- where the Peruvian president lives -- a solemn dignified mood sweeps over the square. Outfitted in regal red, the presidential guards never change positions without a well-attended crowd watching.

Across from the palace stands the colossal Spanish colonial cathedral where Francisco Pizarro, the conquistador who claimed the city for Spain in 1535, is buried in a glass coffin.

Back in the consistent sunshine, try a pisco sour, the most popular native alcoholic drink, made with brandy from white grapes. Or take a minibus from the city center to the Pacific. At sunset, the orange ball of day dips dramatically beneath the horizon.

By bus or car, the journey from Lima to Cuzco requires two or three days. But time- and comfort-minded visitors fly over the snow-capped Andes, as we did, instead of winding by bus or car through them.

Fifty minutes after departing Lima's Jorge Chavez Airport, and perhaps after winning an in-flight bingo game -- as popular aboard Peruvian airlines as peanuts are aboard American -- you land in Cuzco. Once the throne of the Incan empire, Cuzco is now the center of Peruvian tourism. A bright, colorful city, it sits like a jeweled crown within a ring of mountains almost two miles high in the Andes.

White stucco homes with red tile roofs line winding cobblestone streets. Llamas and alpacas are as common in the narrow passageways as playing children. And in the many arboreal plazas, native artists paint, draw or snooze beside their easels.

Women with infants strapped to their backs stand in low doorways, some weaving blankets, some making jewelry and others working on pottery. The country gentlemen, a few wearing knickers and all wearing hats, hurry along the streets, while others tend their shops or tourists.

Most distinctly, not only all the men but all women in Cuzco wear a hat or a cap. According to its variety, shape and color, it tells the birthplace of the wearer's ancestors. For instance, we learned that all the women wearing black derbies came from a tiny village north of Cuzco, and most of them were somehow related. Like a milliner's paradise, others walk the streets wearing brown top hats, multi-colored knit hats and farmer's caps.

An impeccable green countryside surrounds this city of 150,000. Incan dams, ancient stone shrines and intricate wood carvings dot the hillside. Dubbed the Archeological Capital of South America, the city boasts Incan sites, Spanish monasteries and native and colonial museums that take days to explore.

There is so much to see, but before you follow the cobblestone streets that beckon you into the past, rest. Nearly all visitors feel lightheaded from the high altitude and need to lie down for a few hours after arriving.

We cured slight headaches by sipping coca tea, a legally narcotic warm drink made from the same leaves as cocaine. The Quechua Indians native to the region know how good a spot of coca tea can make you feel.

Once you've adjusted to the thin mountain air, step into the past, and nowhere better than at the convent of Santo Domingo are Peru's two pasts -- Indian and Spanish -- linked so cohesively. A 16th-century Catholic Church, also called Santo Domingo, rises over the principle Incan edifice, the Temple of the Sun, where 12th-century Incas paid homage to their sun god.

The devastating earthquake of 1950 uncovered the Incan temple, and since then archeologists have unearthed stone passageways below Santo Domingo that led to storage chambers that once stored gold and silver.

At night the city's most spectacular structure, La Compania, the church of the Jesuits, glows with a hundred lights. An outstanding colonial stone building, La Compania is laid out in the form of a Latin cross. Inside, gold and silver adorn the baroque altar, and 17th-century Spanish paintings drape the stone walls.

In most of the restaurants, you are sure to meet foreign archeologists and travelers. One of the best, La Truca, a cabaret-style restaurant off the Plaza de Armas, serves native and international food as well as the best folk entertainment in the city. Dressed in colorful native costumes, dancers, singers and musicians offer a three-hour show that alone makes the trip to Cuzco worthwhile.

Now only 70 miles from the mystery of Machu Picchu, a traveler is drawn to the San Pedro train station.

For three hours you ride on tracks that carry you 3,000 feet down into the Urubamba River valley and leave you at the base of Machu Picchu. With each passing mile, the valley becomes denser, greener and wetter. Visitors from Augusta to Australia lean out the express train windows shooting rolls of film: first pictures of bustling villages and hills covered with eucalyptus trees; then sun bursting through mountain cracks and the mighty Urubamba hurrying alongside the train on its way to meet the Amazon.

At two quick stops, we stepped off the train to buy hand-woven blankets and alpaca sweaters. With only one daily train run, we knew we shouldn't stray far, but the countryside was so gorgeously tempting that we did -- then had to jump aboard the moving train.

Not long after, the train stopped at a tiny station where six buses waited to complete the last leg of the journey. And for 20 minutes, the bus wound around blind narrow curves.

On the slow ascent, I wondered why Machu Picchu was ever founded here rather than why it was "lost" for centuries. And then I saw it: the stone walls, the terraced fields, the ancient ruins. The Incan city was ready to be reawakened.