Vietnam
Wait until you get to Vietnam to book internal flights. It's much cheaper than booking in the UK. I flew from Hanoi to Hue for £200. I flew from Dalat to Ho Chi Minh City for £30.
There are lots of Vietnam Airlines offices in major cities.
iViVu is the only travel website in Vietnam offering a flight search and booking facility at a great price. It also provides you with travel information on Vietnam.
To enjoy Hanoi you first have to get there, and for that you need Air Asia. Flights from Bangkok on Thai and other airlines used to be 10,000 baht return; now you can get there on Air Asia for 3,000 baht. Go often, it's beautiful.
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