Currently the world’s largest natural cave, the 2.5-million-year-old Son Doong cave in central Vietnam was first discovered by a local farmer named Ho Khanh in 1991 when he’s trying to find shelter from a storm.
Unfortunately, Ho Khanh forgot the location of the cave but it was rediscovered by foreign divers in 2009.
Famous for its breathtaking nature safe from human development, the cave is so big that it has its own climate and ecosystem.

On 1 to 3 April 2019, three British divers started a diving expedition as they were invited to explore the subterranean river system in Son Doong. They are also a part of the team that rescued the 12 boys who were trapped inside a flooded cave in Thailand last year.
The British divers hoped that the underground river of Son Doong would connect with another cave, Thung.

But after they went down and deep inside, it seemed that there’s no ending to the tunnels system and it might be bigger than they expected. They estimated the depth of the river would be 93 meters, but there’s no hint of connection with the Thung cave even after a 77 meters mark.
Looking at the current situation, they believed that Son Doong could be 500 meters deeper than estimated.

“We’ve been to many large cave systems but none of them can compare with Son Doong. It’s a pity that we cannot get a full picture of the underground system of Son Doong this time,” said Jason Mallinson, one of the divers.
They need better equipment to continue the expedition.

As the scale is bigger than they expected, the team was unable to proceed because they needed better equipment for the task. So they chose early April when the water level is at its lowest plus with good underwater visibility, the team planned to come back with helium next year to be able to go deeper than 120 meters.
They plan to come back again next year.

If you’re curious to explore the cave, it only allows 900 visitors from January to August yearly and you need to pay around $5,580 for a trip to Son Doong.
For more great destinations in Vietnam, check out the comprehensive guide here.
Credit: World of Buzz | VN Express