- Hai Van tunnel is one of 30 largest and most modern tunnels in the world. The tunnel is 12 km long, is shorter than Hai Van Pass 9km. The north of the tunnel belongs to Lang Co Town, Phu Loc District, Thua Thien Hue Province, and the north of the tunnel belongs to Hoa Hiep Ward, Lien Chieu District, Da Nang City.

- Hai Van tunnel commenced to be built in August, 2000 and then finished in June, 2005. The project's major constructors were a Vietnam-Japan joint venture, Hazama-Cienco 6, and a joint venture between Korea's Dong Ah construction company and Vietnam's Song Da Construction Corporation.

- Hai Van tunnel consists of 2 tunnels: a main tunnel servicing traffic and an exit tunnel. Main tunnel is 6.280m long, 11,9m wide, 7,5m high, divided into 2 lanes separated by rubber columns; each lane is 3.75 m width. On the left of the main tunnel has the lane with 1m wide to serve the maintenance workers. There are 18 points to park when the transports having the difficulties and accidents in Hue. The exit tunnel with 4,7m wide, 3,8m high parallels the main tunnel and is far about 30m east from the main tunnel. There are 15 tunnels connecting the main tunnel and exit tunnel with each other consisting of 11 tunnels (2,25m wide, 2m high) for the footers, 4 tunnels (4,7m wide, 3m high) for rescue vehicles.

- To operate normally, Hai Van tunnel also has the ventilation system (ventilation tunnel is 1.810m long, 8,2m wide, 5,3m high), ESP tunnel is 153m long, 10,2m wide, 6,7m high, other constructions such as substation 110/22 KV, lights, fan system, 52 cameras, fire alarm devices, telephone stations, radio system, car counting equipment, signage systems and other specialized equipment.