Hangzhou Bay Bridge (simplified Chinese: 杭州湾大桥; traditional Chinese: 杭州灣大橋; pinyin: Hángzhōu Wān Dàqiáo; Wu: Han-tseu-uae du-jiau) is a long 35.7 km (22.2 mi) highway bridge with two separate cable-stayed portions, built across the mouth of Hangzhou Bay in the eastern coastal region of China.

An earlier plan placed the bridge further east, closer to the mouth of the bay, which provided an even shorter travel distance between Ningbo and Shanghai.

The Hangzhou Bay Bridge has significantly shortened driving distance between Ningbo and the Yangtze River Delta region and improved the competitiveness of the Beilun Port.

This choice was made based on the fact that the steel piles would be much stronger against corrosion from the extremely high tidal forces in the bay.

[3] These heavy duty cranes were used to transport massive girders from the shore to the part of the bridge where they would then lift it and put it into place.

Wang Yong, chief director of the Hangzhou Bay Trans-Oceanic Bridge Construction Command Post, described the bridge as being built "in the world's most complicated sea environment, with one of the three biggest tides on Earth, the effect of typhoons and the difficult content of the sea soil.

This technology involves casting (molding) the girder, or bridge panel, letting it harden for no more than three days, and then squeezing it before it reaches its full density.

[5] The third major challenge faced by designers and engineers was an area of toxic methane gas that was discovered roughly 50 meters underground below the location of the bridge.

To do this, steel pipes measuring 60 cm in diameter were inserted into the ground, slowly releasing the methane six months prior to drilling.

[6] A 10,000 m2 (110,000 sq ft) service centre called Land between the Sea and the Sky (Chinese: 海天一洲, Pinyin: hǎi-tiān yī-zhōu) is built in the middle of the bridge.

This centre consists of shopping/exhibition/parking/restaurant facilities, a hotel and a 145.6 m-high (478 ft) lookout tower which serves as a tourist attraction from where to enjoy a bird's eye view of the bridge and the ocean.

The service centre is built on an island, which is a platform resting on piers to avoid obstructing the sea current in the bay.