BEIJING, July 27 (Xinhua) -- The State Administration of Cultural Heritage (SACH) will launch a campaign to crack down on criminal damage to the Great Wall.

The campaign will involve regular inspections and random checks on protection efforts by authorities in 15 provinces, autonomous regions and municipalities.

The SACH will open a special tip line for information about violations and damage to the Great Wall from the public.

Built from the third century B.C. to the Ming Dynasty(1368-1644), the Great Wall stretches over 21,000 kilometers from the northwestern province of Gansu to north China's Hebei Province.

According to SACH statistics, about 30 percent of a 6,200-km section of the wall built in the Ming Dynasty has disappeared, and less than 10 percent is considered well-preserved.

The Great Wall has faced threats from both nature and humans. Earthquakes, rain, wind and other natural elements have left the wall with many decayed and crumbling bricks.

Human activities, such as reckless development by some governments and theft of bricks by local villagers for use as building materials, as well as agriculture near the wall, have damaged the landmark, according to research by the China Great Wall Society.

A lack of protection efforts in remote regions and a weak plan for protection have also contributed to the damage, the society added.

In 2006, China released a national regulation on Great Wall protection. However, Great Wall experts have urged local authorities to draw up more practical measures to better implement the regulation.

This year, Inner Mongolia Autonomous Region included Great Wall protection expenditures in its budget. The government of Fangcheng City, Henan Province, began a campaign for conservation experts and local residents to work together to protect the wall.