Going to Vietnam!

I am leaving for Vietnam on July 1st for 2 weeks. I am meeting a friend who is coming from Europe. We are both flying into Hanoi and then going to move around the country hopefully on motorcycles. I only have a few things that i know I want to do. One is visit the Phong Nha Caves and another is go to Halong Bay. Other then that Im not sure what I want to do other then eat a bunch of food.


Has anyone been there before? Any suggestions on things that I shouldn't miss? Places to stay or avoid.