On Saturday, huge cranes will begin lifting ancient statues, carvings and architectural fragments off the Acropolis, down to a new museum built at the base of the most famous citadel in the world. For the vast majority of these stone remnants of the great age of Athens, it will be the first time they have ever left this rocky summit.

Even as the forces of history washed over this city for millennia, making and unmaking it according to the dictates of three major religions and at least a half-dozen empires, these stone gods and heroes, which once decorated its temples and public spaces, have remained close to their original home. That makes them the lucky ones.

The new museum, designed by architect Bernard Tschumi, has proved controversial from the start. The old Acropolis museum, a low and ugly space built next to the Parthenon, has long been deemed inadequate. Three earlier efforts to build a new museum, in 1976, 1979 and 1989, failed after becoming mired in legal, archaeological and political conflicts. The current museum, which required the expropriation of 25 buildings, has been in the works since 1997, and again legal difficulties delayed it -- so much so that the plan to open in time for the 2004 Athens Summer Olympics is now ancient history.

But Dimitrios Pandermalis, the president of the museum project, says the first visitors will be allowed in early next year, and the museum will have a grand opening sometime in early 2009. At which point, perhaps, arguments about the building will give way to the building's basic argument. Which is simple: Greece wants the marble sculptures that the English ambassador to the Ottoman Empire, Lord Elgin, chiseled off the Parthenon more than 200 years ago. From the ground up, the building is designed to emphasize the Greek claim that the "Elgin marbles" should be returned to Athens, to join together in one place as much of the surviving Parthenon statuary as can be assembled.

Architecture has been used to establish civic identity since at least the time of the Parthenon. But Tschumi's new museum is an attempt to use architecture to shift the terms of a debate about who should possess one of the world's most cherished collection of antiquities. Whether it is an Egyptian artifact looted from a grave during the swashbuckling days of early 20th-century archaeology, or antiquities from Peru sitting in an Ivy League museum, or a Native American object that still has sacred power within a living cultural tradition, there is increasing pressure on established museums to consider the return of art that, in many cases, has helped define them as institutions for decades.

Rarely can the problem be solved easily through legal remedies. Very often the pressure for repatriation is diplomatic, or part of a not-so-subtle public relations campaign. The longer an object sits in one place, however, the more likely it is to become part of a new, and perhaps equally meaningful cultural context.

For many people, a visit to the British Museum means a visit to the Elgin marbles -- and to remove them from London would be to sever one kind of emotional bond in favor of another. And in relatively new countries, such as the United States, the repatriation of art would mean the dissolution of powerful markers of Western and European-derived identity, even if those markers were secured with the fortunes of robber barons or by outright appropriation and even theft.

Tschumi's museum, an austere building, is designed to cut through the complexity of arguments about purloined art and make a direct emotional appeal. It is a large object wedged into a crowded old neighborhood. The entire museum is centered on a concrete core, the same length and width as the core of the Parthenon. On the lowest level of the museum, there are pillars over ruins. On the next two levels there are trapezoid-shaped shaped floors with gallery spaces built around the concrete core. But on the top, the concrete core emerges with a glass box around it, echoing the temple's shape on the hill above. From here, visitors will be able to look up to the Parthenon, with which the new, glass-walled Parthenon Gallery is exactly aligned.

In the Parthenon Gallery, the concrete box becomes a stand-in for the temple itself. Visitors will see the Parthenon frieze running around it, like a belt of marble, illuminated by light flowing through the glass walls. Fragments of the Parthenon's elaborate pediment sculptures, which once sat inside the triangular roof spaces at both ends of the temple, will be placed at the east and west ends of the new gallery, arrayed just as they were 2,500 years ago.

The Elgin marbles, which represent roughly 60 percent of the surviving sculpture that was originally on the Parthenon, will be represented by plaster casts made from the originals now in the British Museum. These casts will be covered by wire mesh veils, to partially obscure them. The idea, according to Pandermalis, is to allow visitors to see the marbles in their original narrative sequence.

"The concept was to restore the continuity of the narrative," says Tschumi, a Swiss-born architect, speaking by telephone from his New York office. And with the veils, which emphasize the absence of the marbles that are in London, the gallery raises a larger question: "Would the building, and the display, be convincing enough so that there would be -- how can I describe it? -- a desire to get those marbles back, on the part of the British?"

Not according to the British.

Jonathan Williams, a curator who oversees the British Museum's European department, praises the new Athens museum as "an extraordinary achievement." But he adds, "The position of the trustees essentially remains that the current distribution in Athens and London provides an important opportunity for different stories about this monument to be told."

This is a slight variation on the museum's formal argument about possession of the marbles, articulated on its Web site. There the emphasis is on the international importance of the sculptures, the number of visitors who see them in London (6 million a year, the museum estimates) and the excellent quality of British stewardship.

"The sculptures from the Parthenon have come to act as a focus for Western European culture and civilization, and have found a home in a museum that grew out of the eighteenth-century 'Enlightenment,' whereby culture is seen to transcend national boundaries," reads a museum statement.

It is a strange use of the word Enlightenment, and a rather galling association of imperial plundering with universal, transnational values. The marbles "transcend national boundaries" in part because Lord Elgin used the Royal Navy to spirit them out of Greece. And while Elgin's gusto for all things classical certainly marked him as a man of the Enlightenment, his removal of the marbles also involved dubious legal dealings and an arrogant disregard for the integrity of the building. It was baldly colonialist behavior by a man who figured Britain, as a great power, simply deserved to own the marbles no matter the cost or the consequences.

And yet, Lord Elgin may have been one of the most hapless imperialists of his time. When he set out in 1799 as the British representative to the Ottoman Empire (which controlled Greece at the time), he planned only to make plaster casts and drawings of the marbles in Athens. His stated goal was the elevation of British taste in art and architecture, not the expansion of England's collection.

Actually taking the marbles was an act of opportunism, justified by a very loose and liberal reading of a short phrase in the legal permission he secured to work on the Acropolis ("and when they wish to take away some pieces of stone with old inscriptions, and figures, that no opposition be made"). The phrase "some pieces" became, in the event, everything that he could get his hands on, and the most infamous act of artistic pillage in history.

At the time, France and England were engaged in a long series of wars that would end only with Napoleon's rustication to the remote island of St. Helena in 1815. Both countries were hungry for antiquities. Napoleon was stuffing the Louvre in Paris with the best world art that conquest could assemble. The French ambassador to the Ottoman Empire told his agents in Athens, "Take all you can. Do not neglect any opportunity to pillage anything that is pillageable."

Arguments in Elgin's defense have run like this: The marbles would have been stolen anyway; the British appropriation of them secured them against neglect and dispersal; and the Turks, at the time, showed little or no interest in saving these vital works. Even the art-loving Venetians had done serious damage to the legacy of the Greeks when they blasted the Parthenon into roughly the shape we know it today while firing on a Turkish ammunition dump in 1687. Elgin had sound reasons to believe he was acting in the best interests of the art.

But Elgin could never have anticipated the writings of Lord Byron, the romantic poet, who fell in love with Greece (and Greek boys) shortly after the marbles were stripped off.

"Dull is the eye that will not weep to see/Thy walls defaced," wrote Byron of the Parthenon in his first great poem, "Childe Harold's Pilgrimage." And he made no mistake about the culprit, Lord Elgin, whom he derided as a hardhearted Scotsman with a barren mind. The poem made Byron famous and confirmed Elgin as a scoundrel in much of the popular imagination.

And in many ways, it laid the groundwork for the modern preservation movement, and ultimately, Tschumi's new museum. When seen simply as functional objects, there's no reason not to update, change or tear down buildings depending on the needs of the moment. Byron was making an argument about preserving a building, as an object with historical and aesthetic integrity, for entirely emotional and sentimental reasons. His poem suggested that some buildings have poetic, even sacred, qualities that transcend time and function.

Which is essentially the argument that the Greeks, and Tschumi's building, are making today. Elena Korka, director of prehistoric and classical antiquities at the Greek Ministry of Culture, says that the Greek position on the marbles' repatriation has evolved over the years.

When the current campaign for restitution began in 1982, the Greek argument was based on grievance and nationalism. The Greeks deserved the marbles back because they were fundamental to Greek identity. But, implicitly at least with all their talk of being the source and origin of all things Western, the Greeks were also arguing that Greek culture had universal, international importance, so much so that one might assume that it should be internationally held.

And the modern Greek connection to the classical past was also, some argued, a fairly arbitrary use of history to forge national identity. Too many centuries of change and cultural intermingling and linguistic and religious evolution had severed the connection between scruffy shepherds of the Peloponnesus, when Byron visited, and the penetrating wisdom of Socrates.

Today, Korka says, the argument is about making the Parthenon whole, not about the Greeks. The Parthenon is "a symbol for Western civilization, a point of reference for the whole world," she says. Therefore, it is in the interests of the world to see its marbles reunited. The Greek culture ministry now publishes a little book that shows, for instance, the body of the goddess Iris on one page (from a frieze held in London), her head on another (a chunk of marble currently in Athens), and the two pieces reunited on a third.

"There is a very large part of the museum which has nothing to do with the marbles," insists Tschumi. Which is true. But the tone -- the fundamental atmosphere of the building -- is set by their absence. The museum emphasizes the need to transcend fracturedness through its proximity, its alignment, and its gallery with mourning veils draped over the casts of the hostage marbles in London. It is a severe building, and a very simple one (in its effect, if not in the architectural challenges it posed).