Deo Ngang, a famous landmark on National Route 1A, cuts across the majestic Hoanh Son Range and serves as a natural boundary between Ha Tinh and Quang Binh provinces. With a length of about 6 km and the highest peak at approximately 250 m, this road not only offers an impressive travel experience but also boasts breathtaking mountain landscapes, attracting tourists and travel enthusiasts alike.
- North: Located in Ky Nam Commune, Ky Anh District, Ha Tinh Province, about 75 km from Ha Tinh City center.
- South: Located in Quang Dong Commune, Quang Trach District, Quang Binh Province, 24 km from Ba Don Town, 27 km from Gianh River, and 80 km from Dong Hoi.
The winding pass, embracing the Hoanh Son forests with majestic and poetic scenery, provides an unforgettable travel experience for visitors.
To facilitate travel, the Deo Ngang Road Tunnel was completed in 2004. The tunnel has a total length of 2,156.4 m, of which the main tunnel is 495 m long, 7.5 m high, and 11.5 m wide. The tunnel features 6 traffic lanes with a maximum speed limit of 60 km/h. The road tunnel has contributed to reducing travel time, ensuring traffic safety, and promoting regional economic development.





