The couple's spirit epitomizes the dedication of those who work to preserve the Han Dynasty Great Wall.

Zhang Jianjun was among the 15 individual cultural relics guardians commended by the National Cultural Heritage Administration on June 10, this year's Cultural and Natural Heritage Day, in Chengdu, Southwest China's Sichuan province.

After returning from the trip, he stayed at home for a couple of days. It was the first time since the start of the year that he had gone back home.

Turning 60, it's nearly time for him to retire from a job he's been passionate about. Zhang Jianjun says that he wants to leave the site to his successors intact and pass on the lessons he learned — to do the work well, one needs to be patient, resilient, brave and determined.

Then, they will spend time with their two daughters, and make up for the couple's absence in their youth. The year they took up the job, which offered a more stable income than they'd had as middle-aged farmers, their little daughter was only 13. She was left behind at home and had to take care of herself mostly, as her elder sister was in Beijing working at the time.

Multiple paths, same goal

While staff like Zhang Jianjun and Chen, not well-educated or professionally trained, persevere in preventing improper construction projects and ensuring proper visitor behavior, as well as preventing animals from intruding, the cultural relics preservation department of Dunhuang has been exploring efficient ways to help the Great Wall resist encroachment of nature, and their vision changes accordingly.

Zhang Chunsheng is working on a project to deal with mild, chronic damage brought about by nature.

Plant roots stretch deep into the ground, weakening structures.

Ants and rock bees like to nest on walls, undermining the already fragile structural integrity.

Preservationists used to focus on reinforcing the body of a wall in urgent need of maintenance, but now they also pay detailed attention to such hazards especially at the bottom of the wall, Zhang Chunsheng says.

He adds that, as a local cultural relics preservation unit with limited staff, technical facilities and funding, they need to apply measures with a low cost. These methods should also be replicable, and the standards for operating them should be accessible to grassroots preservationists and volunteers with basic equipment.