The Shenzhen Metro is the subway or underground system for the city of Shenzhen in Guangdong province, China. The system opened on December 28, 2004, making Shenzhen the sixth city in mainland China to have a subway after Beijing, Tianjin, Shanghai, Guangzhou, and Wuhan. The Shenzhen Metro currently has 5 lines, 118 stations, and 177 kilometres (110 mi) of total trackage in operation.