Mount Erlang Tunnel

The Mount Erlang Tunnel is a road tunnel along the Sichuan-Tibet Highway, which connects Ya'an and Garzê Tibetan Autonomous Prefecture in Sichuan Province, China. The tunnel is 4,176 meters long and was dug through Mount Erlang in Sichuan Province.
It opened on December 8, 1999. Construction took three years and cost 470 million yuan.
It was built to reduce time and replaces one of the most dangerous parts of the highway, which had frequent accidents because of landslides, rain and foggy weather.

New Tunnel

The Erlangshan extra-long tunnel under the same mountain was completed in 2018. It is part of the Yakang Expressway and has a total length of 13 433 metres, making it the 11th longest road tunnel in the world as of 2021. The tunnel passes through several seismic fault zones and its deepest parts are 1 500 metres underground. At its western end, the tunnel links up with the Xingkang Bridge.