For those who wish to journey to Vietnam , Danang should be included on your list. They do have international flights from other Asian destinations such as Thailand etc into Danang or as I've done on my previous cycling trips flown into Danang from either Hanoi or Ho Chi Minh City.
Khe Sahn has always been on my itinerary on route 290 kms up the infamous AShau Valley from
Danang . It's at Khe Sahn that the Vietnamese have opened a small museum and there's lots of remnants of the old Khe Sahn US Marine Base that can still be seen there . By bicycle it's a 3 day ride or take a day and night trip through a local travel agent.