LI YANCHENG was a teenager when people started tearing down what was left of the old City Walls of Beijing in the mid 1960s. It was during the Cultural Revolution when everything old was being attacked.
"I remember adults pulling down the bricks near here where I lived, and I also joined in," he said, as we strolled around a remnant of the wall beside Beijing Railway Station. "At that time people had no consciousness of its historical value."
The people weren't the only vandals. Large portions of the 70 km wall, built mainly in the Ming Dynasty (1368-1644), were destroyed in the 1950s to make Tiananmen Square grand enough for the new communist rulers. More were bulldozed away in the 1970s for a ring road.
But times change. Li Yancheng grew up and studied the Ming Dynasty period at the People's University. He came to appreciate the historical value of the fast disappearing relics in modern Beijing. Now 42, he is a boss of the Beijing Historical Relics Construction Company, and is in charge of rebuilding the very portion of the wall he helped to tear down.
A development company had applied to erect a new office tower on the site but conservationists objected and, to their surprise, got passionate support from local Beijing residents. The council refused planning permission.
What happened next took Li by surprise. In October they appealed in newspapers for the return of bricks which had been taken for use as home extensions or backyard paths. The response was overwhelming.
People turned up with bricks in taxis, trucks and on bicycles. The oldest donor so far has been 89 year old Ma Zongchen, who got his family to search building sites. Another octogenarian, Meng Qingru, brought nine bricks. "It was distressing for me to see the wall taken down," he said. "It was a symbol of Beijing. I never thought I'd see it restored." A disabled girl brought bricks twice.
"It's now become a craze, finding bricks and bringing them here," said Mr Li, as we shivered in the freezing Beijing morning fair. "We had to set up a 24 hour hotline. People ring in the middle of the night to offer their tracks."
They now have 30,000 bricks stacked at the site, waiting to be reassembled into a 115 met stretch of the wall, restored to its original size of 12 metres high and 16 metres wide. The bricks are the size of concrete blocks, 24 kg in weight and grey black in colour. When I lifted one it left a film of adhesive dust on my hands.
They were made from the soil of the Yellow River and brought to Beijing by canal, said Mr Li, pointing with his toe at the stamp of old Ming Dynasty kilns in Shandong province on a loose brick. "They were tested for quality here and if no good, sent back. If still not good enough, the maker was executed."
A total of 30 million bricks went into the complete wall. "I've got a job for life trying to rebuild it," he joked. Though limited in scope, the project is very important to him. "It's not only a matter of pride for Beijing residents, but the wall is also part of the history of the world. We have to build it for young generations to know their past.
Beijing is now a city with glittering high buildings and concrete overpasses - the site is over shadowed by the New Otani Gloria Plaza - and it is unlikely that more than a token stretch of the wall can ever be recreated as an additional tourist attraction in the future.
But in Beijing, as in other world cities, conservation rarely wins out against big money. In a decision reminiscent of Dublin Corporation's refusal to stop building on the Viking site at Wood Quay in the 1980s, Beijing council has pushed ahead with a big city development right on top of one of the most important historical sites found in any capital in the world.
The oldest relics of Stone Age man in central China turned up in December at the bottom of a sixstorey deep crater being excavated for the construction of Oriental Plaza, a giant £1 million shopping mall near Tiananmen Square. The artifacts found at what could be a 10,000 year old settlement may mean a re evaluation of the conventional theory that humans of the Paleolithic period lived in caves rather than the plains around Beijing.
Despite more vigorous opposition from archaeologists and angry citizens, the council decreed last week that "excavation will not affect the construction of Oriental Plaza". The conservationists will not let the matter rest there, but the outcome is likely to be the same as at Wood Quay - a museum in the basement.