Ha Long Bay is one of the most popular natural attractions in Southeast Asia and one of the most beautiful places in Vietnam, CNN said.
It advised tourists to go on a cruise ship or hire a kayak to explore the bay, which is dotted with thousands of islets rising out of the emerald waters.
The most ideal time to visit Ha Long is between March and April and September to November as there is very little rain and cruise conditions are near perfect.
Prices for overnight cruises range from $116-228 per person.
Around a two-hour drive to the east of Hanoi, Ha Long Bay was recognized as a World Heritage Site in 1994 by UNESCO, and voted among the world's seven new natural wonders by Swiss organization New Open World in 2011.
Its popularity rose after Hollywood blockbuster "Kong: Skull Island" was filmed there in 2017.
The 2018 launch of Van Don International Airport, Vietnam’s first private airport, provides foreign tourists with easier access to Ha Long Bay.
The CNN list also included Zhangjiajie National Forest Park in China, El Nido, a coastal town in the Philippines and the Maldives.