(continued)

Archeologists, geologists, tour guides and other experts on the region were also skeptical. Some suggested the Japanese scientists may have trumped up the alarmist report because their research grant was running low.

Others wondered whether Peru's disgraced ex-president Alberto Fujimori, who fled to Japan amid a corruption scandal last November, had not dreamed up the scare to damage the Peruvian economy.

Almost all agreed that though the landslide threat must be thoroughly investigated, the chances of nature defeating this Inca masterpiece anytime soon are almost zero.

"The magnificent Inca works at Machu Picchu will be around intact much longer than the Japanese team who predict their imminent destruction," said Garry Zeigler, an American expert who has been researching the Incas since 1964.

The Inca Construction

The Inca's chose the site of Machu Picchu, on a white granite plateau between two mountains, because they knew the location was not subject to seasonal landslides, Zeigler explained. It may be on geological fault lines, and there is always a risk of surface rockslides, especially in Peru's rainy season, but it is outside the regional earthquake zone and far away from the southern Andean volcanoes.

"The Inca's knew exactly what they were doing," said Nick Asheshov, author of the United Nations' State of the Environment in Peru report for the year 2000. "They built Machu Picchu on a solid slab of granite that is unlikely to break up within the time frame of human history."

Aware of the earth's movements beneath them, the Incas crammed open fissures with stones and cut steps in the tops of "natural rocks' — those still connected to the earth — which they filled with smaller, carved granite bricks, to allow leeway for the stones to shift.

Large cracks are visible in several key buildings, including the Water Temple. But Zeigler confirmed that photos taken by Hiram Bingham show these cracks have not grown in 90 years. Bingham was U.S. explorer who the discovered the city in 1911 after it had lain hidden under thick jungle for nearly 400 years.

"There is gradual subsidence in this fault block," Zeigler explained, "but in geological terms "gradual" means over several million years.

A Brief History

Ironically, only a few hundred Incas lived in this vast, meticulously crafted citadel. And they were here for less than a century before they fled the Spanish conquistadors who arrived in Peru in 1532. The history of Machu Picchu is shrouded in mystery because the Incas left no written records, and the Spaniards never found the city during their three hundred years of colonial rule.

This 8100-acre (3,300-hectare) contruction is considered the best testimony to Inca planning and engineering. With breathtaking jungle mountain views both east and west, the city has a simple, harmonious hierarchy with noble buildings looking down over a broad plaza and humble one-room houses.

White granite boulders were loosened from the surrounding hills, split using water saturated wooden stakes, and painstakingly shaped into building blocks. The more sacred the building, the more perfectly chiseled and smoothed were the granite "bricks," carved to fit snugly together without cement.

The most immaculate example of this craftsmanship is in the Sun Temple, the only round building in the city. Its walls are smooth and molded and its altar stone catches the fist rays of the winter and summer solstice through two carefully positioned windows.

If the Temple of the Sun is geometrical perfection, the Temple of the Condor, where mummified bodies were entombed, is its dynamic, artistic counterpart. Two spread granite wings, carved out of the hillside, soar up from the sheltered paths of the lower city. Between them a beak-shaped stone is set into the ground.

A towering granite wall between two temples at the far end of the city is cut to follow the line of the rugged mountain range it looks upon.

In those pre-wheel days, workers hauled over a thousand tons of sand up from the Urubamba river bed to build and irrigate the agricultural terraces on the edge of the city.

Potatoes were not the only things that benefited from the Incas' irrigation techniques. In a plumbing system that still astounds the experts, water runs from the Water Temple through underground channels (no one knows how they were cut out of the solid rock) into the top "bathroom."

This is a box-shaped room with water piped in at the highest wall, a foot basin from which the water flows into the next in a flight of box bathrooms that step down to the more modest living areas.

As scientists continue to measure this city's seismic volatility, the threat of destruction by tourism seems a far more imminent one. Over 300,000 visitors trekked through Machu Picchu last year, rambling freely over the sacred stones. Somewhere near two million are expected by the year 2005.

Sophie Arie is a British journalist freelancing in Santiago de Chile. She has worked for international news agencies in London and Paris and edited a feature service for America Online.

An overview of the site of Machu Picchu, Peru. Photo: Great Buildings Photo © Kathleen Meredith Single room houses, once thatched, may have been the more humble dwellings but still enjoyed the staggering view. Photo: Sophie Arie The most sacred stone in Machu Picchu, the Intihuatana stands at the highest point in the city. It was damaged in 2000 when a crane was dropped on it during the filming of a beer commercial. Photo: Sophie Arie Windows look over the valley from the chief's house in a smaller settlement along the Inca Trail. Photo: Sophie Arie Terraces and buildings at Machu Picchu. Photo: Great Buildings Photo © Kathleen Meredith View through a stone window. Photo: Great Buildings Photo © Kathleen Meredith A courtyard space. Photo: Great Buildings Photo © Kathleen Meredith   Click on thumbnail images to view full-size pictures.