The Ha-Giang loop is in the mountains of northern Vietnam and supposed to be beautiful.  I'd love to do this loop but I don't want to do it alone and would love some company.  Its a bit off the beaten path but I've read enough about it to know that plenty of people do it!  It's about 400km and you go by motorbike over 5 days.  My dates are flexible.  I'll be in vietnam 5/9-5/28 flying in and out of Saigon and would likely do this trip at the beginning or end of my time in Vietnam.  Likely meet in Hanoi and then bus to Ha Giang and rent a motorbike there.  Check out this website for more info about what I'd like to do: https://www.thebrokebackpacker.com/ha-giang-loop-vietnam-itinerary/