Welcome to the palace of Versailles, Los Angeles-style

High on a hill overlooking LA's urban sprawl, the new Getty Center houses a few surprises. Behind the modernist facade are galleries in perfect keeping with their 18th-century exhibits. Lucy Broadbent is enchanted by the most expensive art institution ever built in the US.

It took more than 100 ocean freighter voyages from Italy to deliver the 295,000 blocks of travertine stone. There are also more than 151 miles of plumbing pipes, five miles of stair railing, 40,000 aluminium panels, 1,962 doors and 165,000 sq ft of exterior glass.

Never before has anything been built like the Getty Center. Billed as America's answer to the Louvre, it might bear better comparison to the palace at Versailles in terms of sheer architectural excess. Costing over $1bn, it is the most expensive art institution ever built on American soil, and that's not counting the value of its contents.

But as the Getty Center opens its doors to the public for the first time tomorrow, it will not simply be the statistical evidence that impresses its first visitors, it will be the surprises contained within its new white modernist walls that will most likely leave the lasting impression.

For, in direct contrast to Richard Meier's stark, linear architectural concepts that mark this clearly as a product of the 20th century, the interior decoration of some of the galleries is so perfectly in keeping with their 18th-century exhibits of French decorative art that you might think you were walking through the palace at Versailles.

Fourteen galleries, including four panelled rooms transported from French mansions, have been designed to evoke the styles of the eras of Louis XIV and his successors through the French revolution.

"The galleries are among the most beautiful rooms for the display of art that have been built anywhere in the world," says art critic, Christopher Knight for the LA Times.

All visitors to the Center arrive via a slow, winding tram ride through hillside gardens (cars are left in an underground car park at the bottom of the hill). At the top, in the vast limestone paved entry plaza, the urban sprawl of Los Angeles stretches miles into the distance below. The position alone of this modern-day fortress, which sprawls across 110 acres on top of one of the hills in the Brentwood district, is enough to justify the rave reviews the museum has been receiving.

A museum, library, auditorium, five institutes, gardens and vast administration wings where the grant programme is reviewed, make up the Center. Indeed, it is so vast that visitors are ushered towards an "orientation center" to get to grips with the place.

But it is none of these edifices which are the jewel in the Getty crown. The Getty's stunning achievement is its presentation of the art - both the paintings and the artefacts.

Perhaps the most daring decision in Meier's design was to illuminate the paintings with natural light. Sunlight and candles were what artists had to work with up to the 19th century, and now the paintings of Raphael, Rubens, Rembrandt, Cezanne, Van Gogh, Renoir, Rousseau, Manet, Monet and many more are being shown as they were created - to extraordinary advantage. The light illuminates them to such stunning effect that you will never see in the electrically lit museums of Europe.

Meier put in skylights with computerised louvers in all the upper levels of the five two-storey pavilions which house the museum. These upstairs rooms all have enormously tall coved ceilings. The louvres regulate the amount of bright Californian sunshine allowed in, and the ceiling height allows the light to be evenly diffused without casting shadows. All the paintings are housed upstairs in this gorgeous light.

Downstairs Meier works more magic still. Light-sensitive works like illuminated manuscripts and drawings are on the ground floor where artificial lighting can be controlled. Down here also is the Getty's coup de grace. What better way to display beautiful 18th-century French clocks, candelabras, bureaux and objets d'art than in an 18th-century French panelled room, removed from the Hotel Le Bas de Montaris in France, restored and installed here?

The interior designer Thierry Despont, a specialist in the beaux-arts style, restored four 18th-century French panelled rooms for this section of the museum, installing beautiful pigeon-blood damask walls and all the fittings of a comfortable palatial room. Ten other galleries are also set up in this style, which has meant that for the first time the museum is able to show its entire collection of French furniture and decorative arts, in the setting for which they were designed, in Regency and rococo styles. The Getty is particularly proud of a panelled Regency salon from 1710 and a neo-Classical salon from 1788 that have never before been displayed. The Getty collection is not vast. But a clever decision was made to divide up the collection into separate small pavilions, each connected by walkways. These passages, with their breathtaking views of the city below, offer mental refreshment for museum-goers. Aware that short attention-spans were a major challenge for art galleries in the 20th century, Meier wanted to build a museum where everyone would want to linger.

Judging by the four-month waiting list to get in, he has more than achieved his ambition.