The Mila Mount Tunnel on the Lhasa-Nyingchi Highway is expected to be opened in September, when it will become the world's highest super-long tunnel.

The tunnel is located at the junction of Lhasa and Nyingchi in the Tibet autonomous region at an average altitude of 4,740 meters above sea level, according to the Mila Mount Tunnel Project Headquarters.

As a key section of the Lhasa-Nyingchi Highway on the National Highway 318, the two lanes of the tunnel are 5,727 meters and 5,720 meters long respectively, according to the project headquarters.