The Incas built this mysterious city here, it is told, to be closer to the gods. It was placed so high in the clouds, at 7,700feet, that the empire- raiding Spaniards never found, or destroyed, it.
Today, visitors to Machu Picchu see well-preserved ruins hidden among the majestic Andes: complete with palaces, baths, temples, tombs, sundials, and agricultural terraces, and also llamas roaming among hundreds of gray granite houses.
But they won't find too many bowls, tools, ritual objects, or other artifacts used by the Incas of the late 1400s. To see those, they have to travel to New Haven, Conn.
Yale historian Hiram Bingham rediscovered Machu Picchu in 1911, and, backed by the National Geographic Society, returned with large expeditions in 1912 and 1915, each time carting out - with supposed special permission from Peruvian President Augusto B. Leguía - crates filled with archeological finds.
But now, Peru is threatening to sue the Ivy League school, claiming the permission was either given illegally or misunderstood. The "treasures of Machu Picchu," states David Ugarte, regional director of Peru's National Culture Institute (INC), were given to the American explorer "on loan."
Peru's tussle with the university is not a unique case. From the time Greece started demanding the British Museum return the Elgin Marbles in 1820, to last month, when Italy demanded that the New York Metropolitan Museum of Art give them back objects including the Euphronios Krater, a 500 BC vase, countries of origin have steadily grown more assertive about retrieving their cultural heritage.
"This is our patrimony. This is everything to us - proof that even though today we are poor, our ancestors lived great and proud," explains Mr. Ugarte. "Bingham said he was going to study those pieces and give them back. It was clear to all they were to be returned."
Yale claims in a Dec. 8 letter to Peru that "the civil code of 1852, which was in effect at the time of the Bingham expeditions, gave Yale title to the artifacts at the time of their excavation and ever since."
Colin Renfrew, professor of archeology at Cambridge University in England, says the key to resolving the case hinges on the answer to "what was the deal between Bingham and Peru at the time?" But the answer to that, he admits, "is very murky."
Peru claims that numerous, documented requests to return the pieces - or even negotiate the issue - starting in 1917, were ignored by Yale. "They always wrote back with different excuses - first they said they needed more time to evaluate the pieces, then, in later years, said they were studying our requests for the return," says Ugarte. But, now, with the 100th anniversary of the city's rediscovery coming up, he says, Peru has had enough.
President Alejando Toledo, the country's first indigenous president, who is set to leave office in July 2006, has - together with his anthropologist wife - made the retrieval of the objects a priority.
"Peru has notified Yale University President Richard Levin that a lawsuit is being prepared if its rights to the archaeological pieces are not recognized," Peru's Foreign Minister Oscar Maurtua announced on Nov. 30. "We are convinced that we have sufficient proof to win in court." INC director Luis Guillermo Lumbreras has said the lawsuit would be filed in Connecticut state court in the next few months, but an international tribunal may make the final decision.
Yale, in its Dec. 8 letter, notes that it sent back some of the artifacts in 1922 (Peru concedes, but says these particular items were "worthless") and stresses that a long, costly lawsuit would be a mistake.
Instead, Barbara Shailor, Yale's deputy provost for the arts suggests a compromise: "We have proposed to collaborate with Peru in overseeing the return to Peru of a substantial number of the artifacts," writes Ms. Shailor. But just as Yale is willing to "...recognize the importance to the Peruvian people of ... the return of this patrimony," so, she would like Peru to "give honorable recognition to Yale for its stewardship of the collection for nearly a century, and in the scientific and scholarly contributions thereby made possible."
In 2003, Yale's Peabody Museum mounted a major exhibition of the artifacts that traveled the US, introducing the wonders of Machu Picchu to more than a million people - just as Bingham's books and articles about "The Lost City of the Incas" did close to a century ago.
Bingham had multiple theories about Machu Picchu: that it was a training ground for Inca priestesses; the last Inca stronghold abandoned as the Spanish invaded; or the city of origin of the Inca empire, which dominated South America from Colombia to Chile for about a century.
Experts now say Bingham got it wrong on all counts, and that Machu Picchu was a summer sanctuary of the Inca Emperor Pachacutec.
Yale points out that its efforts have helped make Machu Picchu South America's best-known archeological site, attracting half a million tourists a year.
The fight over the artifacts is compounded by the fact that each side claims the crates Bingham sent out contained something different. Peru says Yale has in its possession close to 5,000 pieces. And, while even Lumbreras has admitted the site had been ransacked many times over the centuries by the time Bingham got there - it is common to hear Peruvians talk about stolen "treasures."
"Who knows where other - better - pieces are?" says Mariana Mould de Pease, a historian of Peruvian heritage. "I want to know what Yale did between 1911 and 2003 when they mounted the exhibition? Where were all the pieces?"
Shailor says all this is "misleading."
"Yale has approximately 250 pieces of exhibitable quality," she writes. "Yale has no mummies, no gold objects, and only a small number of silver pieces."
Roger Atwood, author of "Stealing History," a book on antiquities looting in Peru, says it is clear Yale is "taking a cooperative attitude" and suggests Peru rely on "ethical persuasion" rather than the courts.
"The artifacts are ... the treasures of Peru's most famous pre-Colombian city," agrees Chris Heaney, a Yale graduate writing a book about the controversy. "On the other hand, Yale has taken care of these pieces for over 90 years.... They are not the 'bad guys' here. They are a well-meaning scientific organization, not looters."
• Ms. Harman is Latin America correspondent for the Monitor and USA Today.