With an area of 3.99 square kilometres (sq.km), Central Business District (CBD) Chaoyang is home to around 3,000 domestic and foreign companies. Like other world-famous districts such as Manhattan in New York City and Zhonghuan in Hong Kong, CBD provides an excellent investment environment, convenient transportation, and a high-speed telecommunications system. Office towers, hotels, first-class apartments and multiple service organizations involved in finance, IT and intermediary service industries make Chaoyang Beijing's biggest and most rapidly developing economic area. CBD has become a symbol of modern Beijing. China World Trade Center, the landmark building of CBD,and CCTV New Headquarter, which is called 'wisty Door" Construction of the 600,000 square meter project began in September 2004 on the 20 hectare site of an abandoned motorcycle factory in Beijing new Central Business District. The CCTV building will transform the usually inaccessible environment of media and television production and give access to the public via the isitor Loop" a dedicated path of circulation, which allows people to view and experience multiple aspects of the production process.