Recommended

1 Hanoi

1 day

2 Ninh Binh

2 days

3 Ha Long

2 days

4 Hoi Han

3 days

5 Da Nang

3 days

Your

Hanoi

Ninh Binh

Ha Long

Hoi Han

Da Nang

Time for

πŸ’‘ Transportations: Nothing beats a scooter for getting around - you can rent one for as little as 5 euros a day. Otherwise, there are buses in Hanoi that cost just a few cents. They're air-conditioned, comfortable and cover the city really well. πŸ‘πŸ»
For inter-city travel, the cheapest options are either night buses or "limousines", which are minibuses. For around 11 euros you'll get a 3-hour ride.
πŸ’‘ Ohers: Don't rely too much on weather apps; they may predict rain all day when all you'll get is a 10-minute shower in the evening.
Also, make sure you research the best time to visit both the North and the Centre, as the weather is completely different in these two regions, but it's definitely a must to experience both!

More to

If you have more time, I recommend you to explore:
πŸ“ Sa Pa: Fansipan Mountain, Hmong ethnic villages, Sa Pa Market
πŸ“ Ho Chi Minh City: War Remnants Museum, Reunification Palace, Ben Thanh Market
πŸ“ Ha Giang: Ha Hiang loop by motorbike
πŸ“ HuΓ©:Imperial Citadel, Nguyen Emperors' Tombs, Perfume River
πŸ“ Phu Quoc: Long Beach, Phu Quoc National Park, Fish Sauce Factory, Sao Beach