Xiamen
Xiamen got its first metro line at the end of 2017, when Line 1 opened and linked Xiamen Island to the mainland side of the city by rail for the first time. In the years since, the network has kept reaching across the water. Line 2, opened in 2019, runs to Haicang through a tunnel about 2.8 km long under the sea, billed as the first undersea metro tunnel in mainland China, and the crossing takes about three minutes. Line 3, opened in 2021, runs from Xiamen railway station all the way to Xiang'an, giving the island its first direct metro link to that district.
