Halong Bay is 500km far away to Sapa & it will be very hard if you have only one day. Please see 2 options below:
Option 1: By bus: you can take an overnight bus from Sapa to Hanoi, arriving about 6:00 AM in the morning. Relax then take another day bus (about 3 hours) to Halong Bay.
Option 2: By Train & Bus: you can take an overnight train back to Hanoi, arriving around 5:00 AM then 3 hours by bus to Halong Bay.
There are some routes you can contemplate features of Sapa with terraced rice fields, ethnic’s lifestyles and culture, rolling hills, and fertile plains., unforgettable treks, lush vegetation, beautiful natural wildlife.
+ Cat Cat Village - Lao Chai Village - Ta Van Village - Ta Phin Village
+ Y Linh Ho Village - Lao Chai Village - Ta Van Village - Giang Ta Chai Village - Supan Village
+ Cat Cat Village - Fansipan Mountain
Cat Cat Village is the best hiking routes in Sapa where you can pass through the best view picturesque with green rice paddies and local tribes wearing colourful embroidery.
Keep in mind that Sapa is hilly destination which is highly recommended for professional cyclist. Both downhill and uphill ride of the various terrace will be interesting and challenging experience for you which Ta Phin Village will never let you down.
Bac Ha market is the biggest market in the northwestern highland. it only occurs on Sunday which is very colorful market with numerous necessities such as spices, cattle, vegetables, farm tools, food and especially wines
Muong Hoa Valley must be the most beautiful sight to soak up the atmospheric rice terraces all the time.