What will the future city look like?
A statue hanging in the Pavilion of Future in Shanghai Expo Park describes the development of cities in a parabolic way.
"When the lights come on, the shadow of the statue, which looks like the skyline of New York City, appears on the white screen in front of visitors. And when the lights come from the right side, the shadow on the left screen looks like Shanghai skyline," says pavilion guide Ni Wenhua.
But the skylines come from unexpected materials -- city garbage, including refrigerators, tyres, bicycles, metal parts, and steering wheels.
"The statue is a warning that the development of cities should not be a process of polluting. It should a harmonious process of coexistence between people and the environment," Ni says.
Designed by Carmen Bueno, of Spanish exhibition design firm INGENIAqed, the Pavilion of Future is designed to show how dreams build the future.
Bueno believes the "dream" drives ideologists, technicians and scientists forward to the future, or, as one of the slogans on the pavilion's walls says, "In yesterday's Utopia was born today".
The ZED Pavilion in the Urban Best Practices Area, near the Pavilion of Future, has a more specific dream.
"Our dream is that all the future houses are 'zero carbon' houses, in which people can live in a harmonious way with nature," says Xu Song, media director of the ZED Pavilion.
The pavilion is two connected buildings with zero carbon emissions.
The pavilion makes full use of solar, wind and bio-energy and ground heat, says Chen Shuo, ZED Pavilion project director.
The Shanghai Eco-home, also in the Urban Best Practices Area, is based on a renewable energy house in Minhang District, southwestern Shanghai, which has a solar energy system on the roof to supply all its energy needs.
Some pavilions promote sustainable lifestyles, such as the white loop-shaped Demark Pavilion, which promotes cycling in the country once known as the "kingdom of bicycles."
"When I was a little child, I saw pictures of China. There were always streets full of bicycles and almost no cars. Now the streets are full of traffic jams and almost no bicycles. In Denmark, it's just the reverse," says pavilion designer Bjarke Ingels.
The pavilion is shaped like a double spiral and visitors can walk or ride a bicycle up the spiral paths and down again, Ingels says.
In the pavilion's pool, children can play in the water and touch the famous Little Mermaid statue.
"The Demark Pavilion wants to show that the sustainable life can increase the quality of life. If your city is clean enough, you can jump into the sea to swim and ride a bicycle around," he says.
"A future city should be comfortable and enjoyable," says Chen Cun, 56, vice chairman of the Shanghai Writers Association.
"The vital part of city should be people. All the construction should oriented for people, so people enjoy convenience and comfort, and have the chance to develop themselves."
Chen believes a city should meet the material and spiritual needs of its residents. "When a city meets all the needs of a person's development, it is an enjoyable city. It will be the trend of urban development in the future."
The idea is echoed by Arild Blixrud, commissioner general of the Norway Pavilion. "When talking about the future, I think about my grandchildren. I want a good place for them to grow up, to be happy young people and to be able to develop themselves. They should live in harmony."
The Norway Pavilion's slogan is "Norway, Powered by Nature". The pavilion is built around 15 "trees" made from Norwegian wood and decorated with Chinese bamboo.
"We bring a message that Norway is very good country for living because we are very close to nature, we are inspired by nature, we are recreating nature and we are concerned about protecting nature," Blixrud says.
"Future cities will be close to nature, and people will live in harmony."