Ha Long Bay

If you have an extra day, it is very much worth venturing out 113 miles east from Hanoi, or about 3.5 hour drive, to capture the majestic scenery of Ha Long Bay in Quang Ninh Province. It was listed as a UNESCO World Heritage Site in 1994. The bay has an area of 600 sqm, including 2,000 islets, most of which are made up of limestone that has gone through 500 million years of formation in various conditions and environments. Ha Long Bay is home to 14 endemic floral species and 60 endemic faunal species. About 1,600 live in the fishing villages on Ha Long Bay

Both day trips from Hanoi on boat tours as well as overnight cruises are available and offered by a variety of tour operators. I would suggest at least a one-night cruise so you could capture the beautiful sunset on the bay and possibly have a swim the next morning.