Covering an area of 11.59 square kilometers, the Beijing Olympic Park is the extension of the traditional Central Axis of Beijing city, which means the continuation of Chinese history and culture. It includes the National Stadium (Bird's Nest), National Aquatics Center (Water Cube), National Speed Skating Oval (Ice Ribbon), and China National Convention Center. Home to forest parks, mountains and lakes, as well as a sunken garden nine meters underground, the park combines Chinese traditional architectural elements with modern architecture, and embodies the concept of "Green Olympics, High-tech Olympics and People's Olympics".