jones_supa writes: The Great Wall of China has been officially declared much longer than previously thought, the Chinese news agency Xinhua reports. Previous estimates of the wall's length were mainly based on historical records: a preliminary study released in 2009 estimated the wall to be 8,850 km long. Recent state survey results however indicate that the wall measures even 21,196.18 km. Tong Mingkang, deputy chief, said that the survey revealed a total of 43,721 heritage sites that included stretches of the Great Wall. Only 8.2% of the original wall remains intact, with the rest in poor condition, according to the report.