That gap in knowledge may soon be closing. Two years ago, the Chinese government launched an ambitious ten-year survey to determine the wall's precise length and assess its condition. Thirty years ago, a preliminary survey team relied on little more than tape measures and string; today, researchers are using GPS and imaging technology. "This measuring is fundamental," says William Lindesay, a British preservationist who heads the Beijing-based International Friends of the Great Wall. "Only when we know exactly what is left of the Great Wall can we begin to understand how it might be saved."
As Sun Zhenyuan and I duck through the arched doorway of his family watchtower, his pride turns to dismay. Fresh graffiti scars the stone walls. Beer bottles and food wrappers cover the floor. This kind of defilement occurs increasingly, as day-trippers drive from Beijing to picnic on the wall. In this case, Sun believes he knows who the culprits are. At the trail head, we had passed two obviously inebriated men, expensively attired, staggering down from the wall with companions who appeared to be wives or girlfriends toward a parked Audi sedan. "Maybe they have a lot of money," Sun says, "but they have no culture."
In many villages along the wall, especially in the hills northeast of Beijing, inhabitants claim descent from soldiers who once served there. Sun believes his ancestral roots in the region originated in an unusual policy shift that occurred nearly 450 years ago, when Ming General Qi Jiguang, trying to stem massive desertions, allowed soldiers to bring wives and children to the frontlines. Local commanders were assigned to different towers, which their families treated with proprietary pride. Today, the six towers along the ridge above Dongjiakou bear surnames shared by nearly all the village's 122 families: Sun, Chen, Geng, Li, Zhao and Zhang.
Sun began his preservationist crusade almost by accident a decade ago. As he trekked along the wall in search of medicinal plants, he often quarreled with scorpion hunters who were ripping stones from the wall to get at their prey (used in the preparation of traditional medicines). He also confronted shepherds who allowed their herds to trample the ramparts. Sun's patrols continued for eight years before the Beijing Cultural Heritage Protection Center began sponsoring his work in 2004. CHP chairman He Shuzhong hopes to turn Sun's lonely quest into a full-fledged movement. "What we need is an army of Mr. Suns," says He. "If there were 5,000 or 10,000 like him, the Great Wall would be very well protected."
Perhaps the greatest challenge lies in the fact that the wall extends for long stretches through sparsely populated regions, such as Ningxia, where few inhabitants feel any connection to it—or have a stake in its survival. Some peasants I met in Ningxia denied that the tamped-earth barrier running past their village was part of the Great Wall, insisting that it looked nothing like the crenelated stone fortifications of Badaling they've seen on television. And a Chinese survey conducted in 2006 found that only 28 percent of respondents thought the Great Wall needed to be protected. "It's still difficult to talk about cultural heritage in China," says He, "to tell people that this is their own responsibility, that this should give them pride."
Dongjiakou is one of the few places where protection efforts are taking hold. When the local Funin County government took over the CHP program two years ago, it recruited 18 local residents to help Sun patrol the wall. Preservation initiatives like his, the government believes, could help boost the sagging fortunes of rural villages by attracting tourists who want to experience the "wild wall." As leader of his local group, Sun is paid about $120 per year; others receive a bit less. Sun is confident that his family legacy will continue into the 22nd generation: his teenage nephew now joins him on his outings.
From the entrance to the Sun Family Tower, we hear footsteps and wheezing. A couple of tourists—an overweight teenage boy and his underweight girlfriend—climb the last steps onto the ramparts. Sun flashes a government-issued license and informs them that he is, in effect, the constable of the Great Wall. "Don't make any graffiti, don't disturb any stones and don't leave any trash behind," he says. "I have the authority to fine you if you violate any of these rules." The couple nods solemnly. As they walk away, Sun calls after them: "Always remember the words of Chairman Deng Xiaoping: ‘Love China, Restore the Great Wall!'"
As Sun cleans the trash from his family's watchtower, he spies a glint of metal on the ground. It's a set of car keys: the black leather ring is imprinted with the word "Audi." Under normal circumstances, Sun would hurry down the mountain to deliver the keys to their owners. This time, however, he'll wait for the culprits to hike back up, looking for the keys—and then deliver a stern lecture about showing proper respect for China's greatest cultural monument. Flashing a mischievous smile, he slides the keys into the pocket of his Mao jacket. It's one small victory over the barbarians at the gate.
Brook Larmer, formerly the Shanghai bureau chief for Newsweek, is a freelance writer who lives in Bangkok, Thailand. Photographer Mark Leong is based in Beijing.