Expo Axis, Membrane roofing structure in Shanghai, China

Expo Axis is a covered pedestrian passage in Shanghai that connects different areas of the former World Expo site. It spans several levels, both above and below ground, and is topped by a roof made of steel and glass.

Expo Axis was built for the 2010 World Exposition in Shanghai and served as the main spine connecting the entire fairground. After the exposition closed, the site was converted into a public area used for shopping and events.

The six funnel-shaped openings made of steel and glass are called "Sun Valleys" and channel daylight down into the underground levels. This name reflects a Chinese idea that light and nature should be felt even in enclosed spaces.

The passage is well signposted and easy to walk through, with escalators and elevators connecting the different levels. It works especially well as a starting point on a rainy day, since the covered sections provide shelter along the way.

The membrane roof covers 65,000 m², the largest of its kind in the world, and is carried by 19 interior and 31 exterior masts plus six steel-and-glass funnels. The design came from SBA International with Knippers Helbig of Stuttgart and New York, heirs to Stuttgart's lightweight-construction school that produced the German Pavilion tent at Expo 67's era and Buckminster Fuller's geodesic dome.