This is an absolute must for anyone visiting Vietnam and enjoying the off-the-beaten-track places with stunning natural scenery. Going from Ha Giang on two wheel (motorbike) is recommended, you can rent your bike from Johhny Nam Tram, top dude. You would also need to get a permit for the region, but you can do that in the hotels where you are staying. Make sure to get armed with a lot of patience as there is very little English (and certainly no other Western language) spoken in this region. The road at first might be a little scary, especially until you reach Yen Minh, but after that it gets more quiet with less traffic of big vehicles. It is probably recommended to take a day and ride around Ha Giang to get used to the bike and traffic before you set out if this is your first time on a bike in Vietnam. The most stunning scenery is between Dong Van and Meo Vac, but there are definitely beautiful spots also elsewhere. In general you can do the whole thing in 3 days, but I would definitely encourage you to stay more and go around to the little villages. Absolutely amazing region.