By BBC reporter Kirsten Magasdi at The Great Wall in Badaling
Booming tourism, along with unauthorised development and erosion, has caused the destruction of two-thirds of China's Great Wall, according to Beijing's official state-run news agency Xinhua.
The authorities have introduced new regulations to protect the wall
The state media's revelation is not new.
The World Monument Fund listed the Great Wall as one of the world's 100 most endangered structures in 2002 for the same reasons.
The Great Wall is China's most famous landmark, drawing millions of tourists every year. In 1987 it was listed as a World Heritage Site by Unesco.
Despite growing international concern about its state of disrepair, authorities have appeared to do little to protect and preserve it.
But as the 2008 Beijing Olympics approach and the Chinese authorities step up programmes of restoration and modernisation, they also appear keen to stem the wall's deterioration and improve its image.
Several parts of the wall have been restored under the Communist rule, but Chinese authorities say restoring even one kilometre of the wall can take around one year and is very costly.
Last August, the Chinese Government introduced regulations prohibiting the exploration of undeveloped sections of the wall, effectively banning tourists such as hikers from so-called 'wild' sections.
Ramblers without official permission could incur fines.
The Bureau of Cultural Relics says the move is to ensure the wall is not further damaged but that it does not mean tourists are always going to be denied access - they must first check and, if appropriate, apply for permission.
"Actually this is a long regulation. It depends on different parts.
"If you want to go to the Badaling section, that's fine, but if you want to go to further parts you need to consult a local tour operator and ask them to try to arrange a visit according to the regulations,"
said Liu Ke Zhi, the Deputy Director General of Marketing for China National Tourism Administration in Beijing.
"The purpose is just to protect and give you information on what you can and can't do," he said.
The regulations are also intended to clamp down on local people who tear down chunks of the wall and try to cash in on unsuspecting tourists by charging their own access or guiding fees.
According to China's Xinhua news agency, the most recent reported damage was in December at Hebei province in northern China where a l4-metre section of the wall had been pulled down by local developers and filled with concrete.
The development had apparently been approved by the local government office but not authorised by China's Cultural Relic department.
The agency reports the developer was fined 100,000 yuan (US$12,000).
The earliest known stages of the wall were built in the 5th century BC, but not linked and extended until the Qin Dynasty between 221-206 BC.
Much of the remaining sections seen today were largely rebuilt during the Ming Dynasty (1368-1644).
The wall was built as a major defence against nomadic invasions from the north and is estimated to have stretched 6,700km from east to west, over mountains and deserts.
The most visited part of the wall at Badaling, about 90km north of Beijing, was the first section restored in 1957 and attracts around 10 million tourists a year.
It is the 'picture perfect' wall often seen on postcards, but what the pictures do not show are the tourist stands selling souvenirs; Mongolian costume-clad women; and camels and fast food outlets that have set up to cash in on foreign tourists.
At Badaling, tour manager Michael Zhang of China Travel International said the Great Wall and Forbidden City were the top 'must see' sites for foreign visitors and he welcomed the authority's regulations to protect the wall.
"They realise the importance and restoring more places is good for the culture and also I think for attracting more tourists," Mr Zhang said.
"All the people here are happy about the Olympics, and the travel companies are very excited about this as a big golden opportunity and it is good for tourism," he added.
Despite the devastating impact that the Sars virus had on foreign travel to China during 2003, the country is still forecast to become the world's top destination by 2020.
The World Tourism Organisation (WTO) estimates that by then China will be welcoming 130 million visitors a year.
The rapid growth is driven largely by pent-up demand to see sites such as The Great Wall because China only opened its doors to tourism in the 1980s.
The wall will attract many tourists attending the 2008 Olympics
Over the next four years until the 2008 Beijing Olympic Games, the China National Tourism Administration will roll out a massive international tourism campaign.
The theme for 2004 is "Catch the lifestyle".