A question originally asked 500 years ago will be answered in 2008. A response to the poser - How long is the Great Wall? - will be answered by two Chinese government departments.

A huge geographical survey of the Great Wall is to be undertaken by China's State Administration of Cultural Heritage (SACH) and the State Bureau of Surveying and Mapping. 

The work will be completed in 2007 and basic Great Wall statistics including the length and layout would be released in 2008, said officials. 

Local governments have been gathering statistics on the Great Wall since the 1980s. "But due to limited knowledge and technology much of the Great Wall is still a mystery," said SACH director Shan Qixiang.

"The government needs to organize a scientific survey so we can have a comprehensive and accurate understanding of the Great Wall," added Shan. 

The departments will jointly establish a database based on the results of their survey to facilitate future research and protection of the Great Wall. Parts of the work have already started in Hebei and Henan provinces.

The Great Wall was built in the Warring States Period (475-221 BC) when separate sections were built in strategic areas to defend China against invasion by northern nomadic tribes. A large part of it is located in poor and remote areas where few people reside. The traditional estimate of length is 50,000 li or 25,000 kilometers.

The main remnants of the Great Wall were rebuilt in the Ming (1368-1644) and Qing (1644-1911) dynasties. Together they were estimated at about 6,700 kilometers.

The Great Wall is generally considered to start at Jiayuguan Pass in Gansu Province and stretches to Shanhaiguan Pass on the shores of Bohai Bay in the east but no one knows exactly the ancient wonder's length.

Scientists and historians say they'll focus their work on the part of the Great Wall which was built during the Ming Dynasty. Records show the Ming portion of the structure meandered through China's Liaoning, Hebei, Tianjin, Beijing, Shanxi, Shaanxi, Ningxia and Gansu provinces, autonomous regions and municipalities. This section has been estimated at 5,660 km in length.

However, experts have advised that only 30 percent of the Ming sections are still standing. Dong Yaohui, deputy president of the China Great Wall Association, said that less than 20 percent of the Ming period Great Wall was reasonably well protected.

As nature and human activity continue to take their toll on the Great Wall the Chinese government has increased efforts to protect the unique historical relic.

On Tuesday they issued a regulation to further protect the Great Wall. It bans all types of vandalism, driving on the structure, removing soil or stonework and building anything on it that’s not designed to protect the relic. 

(Xinhua News Agency October 27, 2006)