Vinh's role as an industrial port city led to heavy destruction by aerial bombing during the war. As a result it has remained a drab, rather uninteresting place.
The train line between Vinh and Dong Hoi to the south takes an inland route different from Hwy 1. There is some excellent scenery along the way. If you're travelling along the coast by bus, consider taking a break here and going by train. There are trains daily from Hanoi to Vinh.
Bus to Phong Savanh (Phonsavan) Laos, with visa available at border. The bus leaves every second day at 06:00.