Southeast Asia forum

Hello fellow travelers -

I'm thrilled to be embarking on my first backpacking trip and my first journey to Southeast Asia in two weeks. I'm traveling with my boyfriend who plans NOTHING and - while I'm envious of his laid-back attitude and aware of the fact that little goes to plan when traveling in Southeast Asia - I would like to have some semblance of an itinerary to help guide us on our way. We'll be arriving in Bangkok late at night on the 17th of March and leaving from Bangkok early on May 1st. I have done a great deal of research and read about so many places that I'd love to see. The problem is that with just short of 7 weeks we'll be stretched thin seeing all the cities, towns, and landmarks I'm interested in.

I'm looking for beautiful scenery, culture, and an adventurous trip. I'm interested in the following (please forgive my spelling):
Thailand - Bangkok, Kanchanaburi, Chiang Mai, Pai, Krabi
Cambodia - Angkor Wat
Vietnam - Sapa, Hanoi, Halong, Ninh Binh, Hoi An, Dalat, Mekong River
Laos - Luang Prabang, Vien Vang

My question is has anyone done a similar trip and have an itinerary to offer up? If you had 6.5 weeks what would your route/itinerary look like?

Thanks a lot for your help!