The Summer Palace is China's largest existing imperial garden claiming a history of over 800 years. Early in the Jin Dynasty (1115-1234), an imperial palace named Golden Hill Palace was built on the present site of the Summer Palace. It now covers an area of over 290 hectares and includes more than 3,000 buildings, including some spectacular halls, pavilions and towers.

Its main configuration consists of Kunming Lake and Longevity Hill. The garden can be divided into three parts: administrative, residential and scenic.

On the one hand, the Summer Palace is testimony to the luxurious lifestyle of the feudal emperor. On the other, it represents an apex in the development of Chinese landscape gardening in terms of scale, layout, craftsmanship and artistic elegance. It was listed as a UNESCO World Cultural Heritage Site in 1998.

The maintenance project will focus on the Cloud Dispelling Hall and the Long Corridor. The contracts will be awarded by means of public bidding.

The hall has undergone several large-scale revamps in the past two centuries. For example, one scheme in 1886 aimed to celebrate the 60th birthday of Dowager Empress Cixi in 1894. The project in 1902 was to repair the damage caused by the Eight-Power Allied Forces.

After 1949, two maintenance projects were implemented, one in 1953-1954 to celebrate the fifth Anniversary of New China and another in 1988-1989 to mark the 40th anniversary of the PRC. Such projects serve a twofold purpose, celebration of major national occasions and the more practical demands of traditional Chinese wooden structures which need major restoration work every 20-30 years.

The Long Corridor was also restored twice after 1949, once in 1958 1959 and then in 1978-1979.

According to Mr. Gao Dawei, vice-president and Ms. Liu Yuan, researcher of the Summer Palace, preparatory work began early last year. A staff team investigated damages throughout the whole garden. That produced thousands of photographs and two books detailing plans for the restoration. These materials helped them establish four principles for the work: guaranteeing safety; protecting existing historical information; adhering to traditional maintenance methods and staying true to the style and appearance of the Long Corridor.

The preparatory work has been unique in its scale. The teams investigation went into painstaking detail. For example, staff even counted the number of glazed tiles on the roof of every hall and clearly marked which tile needed changed or repaired.

The depth of the investigation also helped staff to calculate an exact budget and to apply for an appropriate municipal allocation. The staff at the Summer Palace who took part in the investigation also built up precious experience in dealing with ancient architecture and developed their own methods of protecting and restoring the cultural heritage.

Though the public bidding has not yet started, Gao Dawei frankly admitted that they are facing several perplexing problems. One is the difficulty of the project due to the need for the very highest quality and another is the promise that the Cloud Dispelling Hall and the Long Corridor will remain open to visitors while work is in progress.

The problems don t stop there. There are now fewer qualified craftsmen skilled in the traditional techniques needed for such sensitive renovations.

A declining market for materials relating to ancient architecture has resulted in many of the manufacturers who produced traditional material for relics like the Summer Palace quitting the business.

In addition to these challenges is the sheer extent of the work the team would like to carry out. Partly thanks to the depth of the probe, the damage discovered greatly exceeded initial estimates.

The Qing Dynasty (1644-1911) had a complete system for the yearly restoration of the royal gardens. But in latter years, the royal family simply could not afford the maintenance anymore. The degradations of war in later years followed by the challenges in the early years of New China didn't help matters either.

Over time, wear and tear and inevitable accidents hit every corner. Though the garden now invests some 10million yuan in renovation every year, it remains difficult to 'pay the debt' accumulated over the past century in the short run.

Interestingly, changing times have also changed attitudes about the best way to preserve unique relics like the Summer Palace. Mr. Gao revealed that the old principle of restoring it in its original form, making new materials appear like old ones, had proved futile. The main idea now is to 'restore it as it is'. The value of the Summer Palace, most experts agree, lies in its integral value, not a single piece of wood or stone.