The world-famous Son Doong Cave in central Vietnam has been ranked fourth out of the world's 10 places still not fully explored by Canadian travel site The Travel.
"This enormous underground cave system holds a network of immense caverns and chambers, many of which have yet to be fully explored," the travel site said.
"With its winding passages and eerie underground lake, this cave is a thrilling prospect for explorers," it added.
According to The Travel, Son Doong Cave is home to various species of bats and even some tiny fish colonies. These creatures have adapted to the cave's unique environment and can offer scientists invaluable insight into the evolution of species. Moreover, the cave is a fantastic example of what can be achieved when nature and time work together.
An expedition to the cave costs around $3,000 for four days on a tour exclusively operated by Oxalis Adventure.
Phong Nha-Ke Bang National Park in Quang Binh province, home to Son Doong, was inscribed on UNESCO's World Heritage List in 2003. It features great geological diversity and offers spectacular phenomena while harboring a high level of biodiversity and many endemic species.
Expert geologists estimate Son Doong was formed sometime between two to five million years ago, before local farmer Ho Khanh inadvertently stumbled upon its enormous entrance in 1990.
It remained untouched until 2008 when Ho Khanh retraced his steps to its misty opening, and until 2009 alongside Howard and Deb Limbert of the British Cave Research Association. The intrepid speleologists conducted Son Doong’s first official survey and concluded that it was the largest natural cave on the planet.
The other places named on the list in order are: The Aleutian Islands, Antarctica, the Atacama Desert, the Congo Basin, Kaieteur Falls, the Namib Desert, the Mariana Trench, the Sahara Desert and the Amazon Rainforest.
Early this month, Son Doong was ranked 10th out of the world's 10 most incredible caves by the travel site.
"Popular for being one of the largest caves in the world, Son Doong Cave in Vietnam is one of a kind. Translating to “River Mountain Cave”, it is believed that the cave has been formed by Rao Thuong River erosion into the base of a limestone mountain, Truong Son. Hence, a large tunnel was formed underneath," The Travel wrote.
Being 200m high and 175m wide as well as 9.4km in length, the cave could fit a 40-story New York skyscraper inside.
"The most fascinating elements are a thick forest that's been growing in the cave for years, as well as towering stalagmites, phytokarst, cave pearls, and roof collapses. Also, It requires two days of intense jungle trekking and river crossings to reach the entrance of Son Doong Cave," it noted.
In April, 2022, Google Doodle honored the world's largest cave Son Doong.
Inside the cave’s undisturbed inner chambers, scientists discovered a wealth of record-breaking geological formations, including the world’s largest limestone pearls and tallest stalagmite, said Google Doodle.
Giant sinkholes situated further into the cave’s depths allow for sunlight and rain to nourish two pristine jungle ecosystems, which are home to flying foxes, the world’s only monkeys to live underground, and eyeless white fish, Google Doodle added. One of these thriving rainforests is so vast, it even has its own localized weather system.