A Green Corridor built by the year-end over Beijing's North Fifth Ring Road will link the southern and northern parts of the forest park, a Games landmark.

The wildlife can freely roam the entire park using the bridge - and so can you.

"Although the design has been revised many times, the corridor remains."

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To make the park a whole, the designers conceptualized the corridor above the road. "In the original design during the first round of bidding for the park, there was a huge mountain in the north and the main lake in the south," Hu said. "A long slope was to start from the lake area to the mountain above the road to link the two parts.

"But after careful scrutiny, we found that if we put the mountain in the north, it would need large quantities of earthwork to make it visible from the south. So we finally decided to have the mountain and lake together in the south."

The idea of a green corridor came up during the second round of bidding. According to the final plan, it is 200 meters long and 60 to 100 meters wide, with a layer of soil 1-3 meters deep.

A quarter of the corridor will be planted with tall arbor, while the rest will be covered by shrubs and low arbor.

"The whole corridor will be covered in green," Hu said. "For motorists driving under the corridor, the green bridge will be visually stunning."

The whole project is so complex that it is hard for one organization to handle. The design has been completed by Hu's team and Beijing Beilin Landscape Architecture Institute affiliated to the Beijing Forestry University will be in charge of the project drawing. Beijing Urban Engineering Design and Research Institute Co. Ltd will take charge of designing the bridge.

As the first of its kind in China, the bridge posed many technical challenges to the designers, such as controlling its weight and preventing frostbite for the plants.

They were solved by interacting with "consultants to similar projects overseas and experts from home and abroad," Hu said. "In the design of a park in China, we seldom meet such a complex situation."

Example for green Beijing

Located at the north end of Beijing's central axis, the concept of the Olympic Forest Park is called "Axis to Nature".

During the Beijing Games, the tennis, archery and hockey events will be staged in the park, which is also expected to be a "back garden" for the Games.

Ten times large as the Beijing's Beihai Park, the oldest and most complete extant imperial garden in the capital, the forest park is believed to benefit the city's environment.

"Since the density of plants is high in the park, it will help a lot in improving the air quality and reducing air pollution," said Hu, who worked for Sasaki Association in the United States before he came back to China for the Olympic project.

"We are now doing research on the long-term impact that the park will have on Beijing, which may take up to 10 years."

Hu admitted that one such park won't solve the city's pollution woes but it "will make a great contribution to the green land in Beijing and provide useful data for future city planning."

"It will serve as a guide for improving Beijing's ecology."

After the Games, the park will be open to the public and some facilities will be added, such as restaurants and playing facilities for children.

But Hu was quick to promise that man-made facilities would not destroy the natural condition of the park.

"There will still be large green places; and only battery cars are allowed to get to the game facilities or playgrounds while all motor-driven vehicles park outside."