LONDON — This weekend, the new museum of the Acropolis will open its doors in Athens, in a striking modern building situated at the foot of the rock itself.

For a long time, it has not really been possible for a visitor to Greece to visit the buildings on that most famous of all hills, and also the sculpture that used to adorn them in the days of the cult of Pallas Athena.

Atmospheric pollution and structural weakness necessitated the protective removal of a good number of the statues and carvings, and bureaucratic and political delays kept on putting off the day when a serious gallery for their exhibition could be provided.

Now, however, it will be possible for a tourist to walk around the temples of the Acropolis — which themselves have been undergoing an extensive and careful restoration — and then to stroll around a museum, within sight of the temples, where the carvings of Phidias and others are at last again on display.

I was fortunate enough to be given a tour of both sites earlier this year. I think that nobody can fail to be impressed by the combined efforts of Bernard Schumi, the Swiss architect, and Dimitrios Pandermalis, the museum’s director.

The crucial floor is the top one. Here, all the available treasures of the Parthenon have been lovingly and logically arranged in a gallery that is layered differently from other levels so as to replicate and mirror the layout of the temple, up at which it directs the visitor’s gaze. Given all the hazards of time and chance and weather, and all the vicissitudes that the Parthenon has suffered down the milennia, this is the nearest that one can currently come to a full enjoyment of the aesthetic whole.

But that’s where the rub lies. A huge portion of “the available treasures” of the Parthenon have been segregated from the main body and cannot be seen in harmony with it. I am referring to the so-called “Elgin marbles”: the huge chunks of the frieze, the pediment and the metopes (panels) that were quite literally “ripped off” from the Parthenon in the early 19th century, and carried off to Britain, where they were supposed to decorate Lord Elgin’s private home in Scotland. Only his bankruptcy saved them from this fate, and he contrived to sell them to the British government, which holds them to this day in the British Museum in London.

The “Elgin line,” of sculptural partition and annexation, runs through a poem in stone that was carved as a unity and that tells a single story. It even cuts through figures and characters in that story. The body of the goddess Iris is now in London, while her head is in Athens. The front part of the torso of Poseidon is in London and the rear part is in Athens. This is grotesque.

Recently, President Giorgio Napolitano of Italy paid a visit to the Acropolis Museum in order to return a fragment of the frieze — the foot of the goddess Artemis — that has been sitting for years in the Salinas Museum in Palermo. His generous gesture in helping reunify the masterpiece of the sculptor Phidias has been equaled by the Vatican museum, which has returned the head of a young man from panel No. 5 of the north frieze, and by the museum at Heidelberg, which has given back the foot of a young man playing the lyre on panel No. 8. But, still, huge expanses of the sculpture, with its honey-colored patina warmed by centuries of Attic sun, are represented in absentia by a doleful white plaster-cast simulation of the exiled brothers and sisters.

How long can the British authorities cling jealously to the loot of their former ambassador to a long-vanished Turkish empire? (Greece was a vassal state when Lord Elgin’s men showed up with their crowbars and cranes.)

For a long time, the British Museum did have a couple of plausible arguments in its quiver. It could try to maintain that restoring the marbles to Athens would set a precedent that might empty great museums of their collections. And it could call attention to the fact that the Greeks had nowhere to house the sculptural marvels.

The first argument was never as strong as it sounded: Where is the court that decides that an aesthetic gesture is a “precedent”? Have the Hittites and the Babylonians now besieged the Vatican for the return of every other treasure ever moved? Don’t be silly, in other words.

The only precedent that has any value is the good example set by Italian and German museums which understand that it makes no sense to wrench apart, and keep apart, a magnificent work of art.

As to the second objection, having dithered for years in a way that drove all of us Philhellenes nearly crazy, the Greeks have now excelled themselves in creating a place worthy of its breath-taking contents.

It is not a question of denuding one great and old European museum, so much as of completing another great and new one. The British people, when asked, have repeatedly shown that they want to do the right thing and reunify the sculpture. It is impossible to visit Athens and not yearn for the day when Britain decides to right an ancient wrong and show that a beautiful artefact is more than the mere sum of its parts.

(Christopher Hitchens is the author of ‘‘Imperial Spoils: The Case for the Reunification of the Parthenon Marbles’’ and a columnist for Vanity Fair.)