Sea tunnel cuts travel time in Shantou

An underwater tunnel connecting the north side to the south side of Shantou Harbor in Shantou, opened to traffic Wednesday, significantly cutting travel times in the Guangdong province city.

Construction on the 6.68-kilometer tunnel began in 2015 and cost 5.7 billion yuan ($790 million).

Engineers on the project had to overcome significant challenges facing the tunnel's construction, such as it passing through various compositions of rock and being located in an area that has historically recorded strong earthquakes.