With his plasticrimmed glasses and modest demeanour, Dong Yaohui easily blends in among the crowd.

Little do people know that this simple man has achieved the impossible.

In 1984, he trekked the entire length of the Great Wall for the first time in history.

Eighteen years after his unprecedented and legendary hiking tour, the Great Wall has become an inseparable part of the life of Dong, now the secretary-general of the Great Wall Society of China.

Sitting in his small and disorderly office at the foot of Badaling, a section of the Great Wall north of Beijing, Dong said that he would like to say "Please let me off!" to the Great Wall if it could hear.

He explained that after devoting the past two decades to the wall, he is tired, and needs a rest.

He said he has a complex relationship with the wall. While he loves it, it also makes him sad.

A long journey

In the early 1980s, when China began its reform and opening-up not long after the end of the "cultural revolution" (1966-76), many overseas travellers applied to the Chinese Government for permission to hike the Great Wall.

Dong, who grew up at the foot of the Great Wall in Qinhuangdao in North China's Hebei Province, was also planning such a trip.

He spent two years preparing for it, reading as many books on the Great Wall as possible.

He also exercised and trained every day to build up his endurance level and physique.

On May 4, 1984, at 27 years old, Dong set off from Laolongtou (Old Dragon Head), the starting point of the Ming Dynasty (1368-1644) Great Wall.

The 2,000-year-old Great Wall is actually a series of walls built and rebuilt by different dynasties over more than 1,000 years, between the rule of China's first emperor - Emperor Shihuang of the Qin Dynasty (221-206 BC) - and the Ming Dynasty.

Joining Dong on his trip were his friends Wu Deyu and Zhang Yuanhua.

It took them 508 days to reach the western end of the Great Wall at Jiayuguan in Northwest China's Gansu Province. They had covered some 6,700 kilometres.

Along the way they carefully reviewed the 110 counties they passed and collected a great deal of precious first-hand data, important for protection efforts for the Great Wall.

Dong admits today that he had some selfish motives when he decided to walk all the sections of the Great Wall.

Prior to the hike he had a secure job as a wireman in Qinhuangdao. While most of his peers only earned 40 yuan (US$23 at the rate then), Dong's monthly salary was three times that.

But he was unsatisfied. Using his interest in literature and hoping to write his own works one day he longed for something different. To him, a hiking tour of the Great Wall would bring inspiration and also great change to his life.

New career

The hike did change Dong's life, but not in the way he had expected.

From then on, he would never escape from the Great Wall. To this day, Dong is still unsure of whether this was a stroke of fortune or bad luck.

"It is just like being pushed by a force that you cannot resist," Dong said.

Between 1985 and 1989, on the recommendation of Huang Hua, the former vice-premier of China and president of the Great Wall Society, Dong studied geography and history at Peking University, the top university of China.

At the same time, Dong published a series of books and papers on the study of the Great Wall, which became the most important part of his life.

In 1998, Dong Yaohui accompanied Bill Clinton, then US president, on a visit to Mutianyu, another section of the Great Wall in Beijing.

Winding up and down across deserts, grasslands and mountains, the Great Wall was first built to protect the Chinese empire from marauding tribes from the north.

"Only a nation which longs for peace would spend such a great deal of manpower and material resources to build the Great Wall," explained Dong when Clinton asked why the Great Wall was built.

He has been trying his best to prevent any demolition and destruction of the Great Wall, although it has proved a tough task.

Unlike other cultural relics which can be protected by closing them off to visitors, the Great Wall, which stretches 6,700 kilometres from northern to northwestern China, can never be locked away. It is therefore very difficult to find an efficient way to protect it.

For centuries, the Great Wall had to sustain not only wind and rain erosion but also war. In the past century, it has suffered more man-made destruction, as people often removed bricks from the Great Wall for their own use.

"Currently we do not have special laws for the protection of the Great Wall, so it is difficult to prevent such removal," said Dong.

Once he found that in Bataizi village in Zuoyun County, in Northwest China's Shaanxi Province, local villagers kept picking up bricks at the local section of the Great Wall to build houses.

Dong appealed to local governments at the township and county levels, but the officials did not see what the problem was.

The practice was stopped only when Dong turned to the provincial government for help.

"We need to increase the entire nation's awareness of the importance of protecting the Great Wall," said Dong.

Difficult mission

The uphill battle to save the wall has taken its toll on Dong. He says he often feels tired and frustrated.

This is one reason he wants to leave the Great Wall for a period of time. He is currently looking for a successor.

"After finding an appropriate successor, I will bid farewell to the Great Wall and do something different," said Dong.

He hopes to spend more time writing poems and hopefully live out his unfinished dream of becoming a poet and a writer.

He also has a more ambitious plan to hike the coastline of China, from northeastern China's Liaoning Province to the southwestern Guangxi Zhuang Autonomous Region.

"Actually I had planned to do that before the Great Wall hike. But after finishing that trip, my life was so attached to the Great Wall that I barely found time to start a second trip," said Dong.

But Dong also feels that his life will always be, in some way, devoted to the wall.

"I feel a strong sense of obligation for the Great Wall, so I don't think I can ever leave it," said Dong.

( China Daily July 30, 2002)