Twelve lighting rods disguised as trees will stand on the sides of unopened sections of the Badaling Great Wall by the end of 2014, helping to protect the cultural site, the management authority of the section said.

The lightning rods, made to look like trees, to blend in with the surroundings, are up to 15 meters tall and stand 2 meters from the sides of southern unrestored sections of the Badaling Great Wall.

"Five others will be installed by the end of 2014 to protect the northern part," said Ding Haitao, the official in charge of the project of the management authority of Badaling Great Wall. The first seven have been protecting the wall since the end of 2013.

The hollow lightning rods, made of steel, cost 200,000 yuan ($32,600) each. Their installation is time-consuming as workers have to haul them by mule because of the steep mountains.

"By the end of this year, the whole section, including the open and closed parts, will be protected by lightning rods," he said. But he stressed that the unrestored section will not open in the near future.

The Badaling section, the most visited part of the Great Wall, is 7,441 meters long. Only 3,731 meters of that is open to visitors, leaving two subsections in the south and north closed.

In the open section of Badaling, regular lightning rods have been set up in the watchtowers. But the installation would be more difficult in unrestored sections because many of the bricks are loose.

"We adopted the disguised lightning rods to make them work with the environment," he said.

Many of the wall's visitors climb these unrestored sections to avoid crowds.

Several visitors in closed sections have been hit by lightning in recent years, killing or badly injuring them.

The tops of mountains, hills and buildings are prone to lightning strikes, making people on top an easy target, said Song Pingjian, an expert on lightning at the Beijing Meteorological Bureau.

"These 15-meter rods will work, protecting the walls and visitors," he said.

The management authority of the section invested more than 8 million yuan to repair and protect the section from April to October 2013.

zhengjinran@chinadaily.com.cn