Paradise cave in Phong Nha - Ke Bang National Park (Source: quangbinhtourism.com)

Lonely Planet describes the national park, which was recognised as World Heritage twice by the UNESCO in 2003 and 2015, as a paradise for cave explorers.

The park contains the oldest karst mountains in Asia, formed approximately 400 million years ago. Riddled with hundreds of extraordinary cave systems and spectacular underground rivers, Phong Nha is a speleologists’ heaven on earth, the site said in its article.

“The caves are the region's absolute highlights, but the above-ground attractions of forest trekking, the area's war history, and rural mountain biking means it deserves a stay of around three days”, the travel site said.

“Top experiences in Vietnam” voted by Lonely Planet's include Hoi An, Phong Nha-Ke Bang National Park, Ha Long bay, Hue, Ho Chi Minh city, Ha Giang province, Cat Tien National Park, Bac Ha market, Phu Quoc island, Hanoi, Con Dao island, Ba Be National Park, Sapa trekking, and Mui Ne./.

CPV/VNA