Zhongnanshan Tunnel, or Qinling Zhongnanshan Tunnel in Shaanxi province, China, is the longest two-tube road tunnel in China. It is also the fourth longest road tunnel overall in the world, after the Lærdal Tunnel in Norway, the Yamate Tunnel in Japan and WestConnex in Australia. The 18040 m long tunnel, crosses under the Zhongnan Mountain (Zhongnanshan). It opened on 20 January 2007, becoming part of the Xi'an-Ankang Highway between the Changan and Zhashui counties. The cost to build the tunnel was 3.2 billion yuan (US$410 million). The maximum embedded depth of the tunnel is 1640 metres below surface level.