The new Greek Acropolis Museum

The Acropolis will this year have a museum fit for Greece’s greatest treasure, the Elgin Marbles

A new museum will open in Athens later this year. No big deal, you might think. You’d be wrong. The New Acropolis Museum is not merely a dazzling piece of modernist architecture, but the latest gambit in a 200-year campaign for the return of the Elgin Marbles.

The museum, which has been 30 years in the planning and has cost the Greek government more than £100m, will at last provide a permanent home for the greatest treasures of the classical period, safe from the city’s corrosive, polluted air.

Built in the shadow of the Acropolis, it will display the sections of the marbles owned by Greece – alongside plaster copies of the “missing” sections that reside in the British Museum.

Whether the trustees of the British Museum will be persuaded to give up one of their biggest crowd-pullers, only time will tell.

But regardless of the outcome, the Greek authorities have created a world-class attraction, as I discovered recently on an exclusive tour with the museum’s curator, Professor Dimi-trios Pandermalis.

First, the history. In the early 19th century, the Parthenon was under attack by looters. Lord Elgin, the British ambassador, hired a team of workers to hack away at the monument, taking many of its finest sculptures and large chunks of the marble frieze that lined the inside rim. Elgin shipped the treasures back to England and then sold them to the British Museum for £35,000.

Fast-forward to the late 20th century. The marbles remain divided. Scientists discover the pollution in Athens is eating into the fabric of the Parthenon. The original Acropolis museum, built in the late 19th century, is cluttered and poorly maintained.

A new museum is planned.

It took 25 years of wrangling before an architect was chosen: the controversial, Swiss-born Bernard Tschumi. His high-tech angular design – all glass, concrete and marble – stands in bold contrast to the monuments on the Acropolis. It’s a huge two-fingered salute to traditionalists, as emphatically modern and pleasing as IM Pei’s Louvre Pyramid in Paris.

Problems began as soon as the first spadeful of earth was dug. Beneath the site, builders discovered the remains of a settlement dating from the 4th century BC. Before each foundation was laid, protracted negotiations took place between architects, engineers and archeologists.

The result, though, is astonishing. The three-storey building appears to float over the ground on concrete piles, while beneath it the entire 4,000 sq metre site has been preserved. As you approach the entrance, you look down through glass panels cut into the plaza floor to see more than 2,000 years of history below, including immaculate mosaics.

Once inside, you climb a glass-floored ramp lined with some of the 50,000 artefacts found during the dig. “There are lifts, but we want people to walk up to remind them of the walk to the top of the Acropolis hill,” said Pandermalis.

We then went into a vast gallery designed to house 120 sculptures from the Archaic period. Daylight flooded in through floor-to-ceiling windows and glass panels high above our heads.

“The light is so beautiful in here, and it changes with the time of day and the seasons,” said the professor, standing before a towering statue of a goddess. “Look at the texture, the detail, it’s so soft. You can’t get that with artificial light.” I admired the quality of the marble. “We spent a long time choosing it,” he said. “It comes from Helicon, the sacred mountain of the Muses.”

The sheer scale – 10 times the size of the original Acropolis museum, with 14,000 sq metres of floor space – means exhibits have room to breathe. Visitors can wander between the thick concrete columns to find fresh angles and perspectives. It feels more like a temple than an exhibition space.

Beautiful though it was, Pandermalis was clearly anxious to get me up to the top floor, a huge glass-walled gallery where the treasures of the Parthenon will be displayed. Even without any exhibits, this would be a stunning building, with panoramic views across the city.

Wrapped around the central core of the gallery at eye level is the 160-metre-long frieze, with the Greek originals – coated in a soft brown patina – standing alongside white-plaster copies of the sections removed by Elgin. The effect is awe-inspiring. For the first time, visitors can see for themselves the travesty of splitting the marbles.

“It’s clearly ridiculous if you have a body in London and a head in Athens to keep them separate,” said Pandermalis. “Reunification is not just an emotional issue, it is a logical one. It’s a basic principle of archeology.”

With 2m people expected to visit the museum each year, the Greeks hope that public opinion will slowly force a change of heart in London. That looks unlikely in the near future.

The official line from Great Russell Street is that the British Museum is a superior home because it provides a “unique overview of world sculpture”.

After a recent visit to Athens, Dr Andrew Burnett, deputy director of the British Museum, said he was “very impressed”. So does the new building move the argument forward? “No,” said Burnett. “There is no proposition on the table [to return the marbles to Greece], so the subject has not been discussed by the trustees.”

Whatever the arguments, when you stand in that gallery, looking at the missing sections and gazing across to the Parthenon, it is hard not to feel an emotional tug. It may have been 30 years in the making, but this museum has been worth the wait.