Lạng Sơn is 155 kilometers to the northwest of Hanoi and National Highways 1 and 1 A and passes the Chi Lăng pass (the site of Lê Lợi's victory over 100,000 Ming invaders from China in 1427) and Bắc Giang on National Highway 1A. Lạng Sơn is 135 km from Cao Bằng on the National Highway no 4.