For nearly a century, one of the most opulent structures inside Beijing's Forbidden City, the ancient palace of China's emperors, has sat decaying and unseen by the public. Now, a massive restoration project funded by American philanthropists is set to return the retirement lodge of the 18th century Emperor Qianlong to its former glory.

Walking into the lodge is like stepping into a time capsule. The dust, torn wallpaper, and a musty odor are all signs that it has been a long time since anyone has paid any attention to the vast maze of richly decorated chambers.

A theatre pavilion covered with dust sits in the center of the largest chamber, evoking a time when the sounds of Chinese harps, violins, and Peking opera filled the rooms.

The retirement lodge was built between 1771 and 1776, during what was the height of China's Qing dynasty.

It was in this exquisitely designed four-courtyard garden that Emperor Qianlong, lover of the fine arts, enjoyed music and other entertainment on demand in the years before his death in 1799.

The emperor distinguished his rule by opening up reclusive China to the West, as his lodge reflects with a mix of ornate Qing dynasty decorations and Italian paintings.

The walls and ceiling are adorned with intricate woodcarvings, jade, embroideries, and large paintings created by Italian Jesuit missionary Giuseppe Castiglione and his students. All are still visible under a thick layer of dust.

The complex has sat empty and decaying since the fall of the Qing dynasty in the early 20th century. Legend has it that the complex was jinxed.

Historians say servants murdered a palace concubine by tossing her into a lodge well at the request of the Empress Dowager Cixi more than a century ago.

But recently the World Monuments Fund, a private American organization, approached Chinese officials with a proposal to restore the lodge. WMF director Bonnie Burnham says American philanthropists have donated the funds and U.S. experts are providing technical assistance in art restoration and preservation.

"We have been working to develop the methodology and solutions to the problems confronted by the fine paintings, ornate interiors, and beautiful fragile materials of the lodge of retirement. In 2004, we are looking forward to have our Chinese counterparts visit us in the United States for a technical exchange mission," she said.

Li Ji is the executive deputy director of the Palace Museum. Speaking through a translator, he says the exchange with the United States may provide an opportunity for Chinese artisans to re-discover lost arts.

"Some of the skills are no longer available today and it is very difficult for us to trace the records about those skills," he said.

The World Monuments Fund's Bonnie Burnham explains why she believes Americans want to support a project so far from their own country.

"It is really a part of a larger interest in the world, an opportunity to deepen one's knowledge, the sense that our origins are very broad in America," explained Ms. Burnham. "Philanthropy is very much a part of our society so we see this as almost a kind of diplomatic gesture, but from the civil sector of the United States, from its people to the people of China."

The restoration project is due to be finished in 2006, at which time only a limited number of scholars and academics will be allowed to enter the lodge.

Despite the restoration, museum officials say the interior will remain too fragile to endure the wear brought by the thousands of tourists who visit the Forbidden City each week.