I've been to Sapa and really want to go back there soon. Not only do I love its cool year-round temperatures but also the beautiful scenery. The people I met when I was there were amazing. They walked all the way from their home villages deep down in the far valleys and up to Sapa for their daily local product trading. The food was so good for me and I bought lots of local vegetables to bring back to my dear family in Hanoi.
I think Hoian is somewhat like Hanoi. I like the lanterns that light up the ancient town at night. I like Pho which you can anywhere and a speciality food they call Cao Lau. Definitely the Cao Lau is simply the best local speciality that you could find almost any corner of Hoi An.
"I haven't yet travelled to the South and there are so many great places to choose from I don't know where to start. But I am sure the first place I go with be my favorite place! Maybe I'll go to Dalat...or maybe Nha Trang...or maybe..."
Tip for Sapa: Ask for the boiled vegetable in your menu called Xu Xu (pronounced Su Su). It is so nice that I did not feel that I had enough on my last visit - and I ate a lot!.
Tip for Hoian: Every Lunar Month, on the 14th day, there is a full moon night in Hoian, when the old town is lit by the moon and houses are lit by graceful and colourful lanterns. Make sure you don't mix up your calenders.