Architecture, Building and Structure Design Yilong International Centre Office by Tengyuan Design Yilong International Centre is an office complex in Qingdao, China. Two towers are linked by an aerial bridge placed on the top of the lower building. The bridge holds a shared pavilion space and creates a vertical circulation loop between the two towers. Stepped retreat platforms face the landscape, so the building reads like a scattered group of mountains. The towers use concrete frame core tube and frame-shear wall structures, and the bridge uses a multi-truss steel structure. The design links a dense urban area with the nearby mountains and sea.