The world's longest cross-sea bridge has been opened in China. The Jiaozhou Bay bridge is 26.4 miles (42 km) long and links China's eastern port city of Qingdao to the offshore island Huangdao. The world's longest cross-sea bridge has been opened in China. The Jiaozhou Bay bridge is 26.4 miles (42 km) long and links China's eastern port city of Qingdao to the offshore island Huangdao. Source