Son Doong: world’s biggest cave, can you tour it - why Vietnam attraction is being featured in a Google Doodle

Google’s Doodles usually mark historical anniversaries, national holidays or other, widely celebrated events.

So why is it singing the praises of the Son Doong cave today?

Well, 14 April 2022 marks 13 years since the cave was “officially” discovered. But just why is the cave noteworthy enough to be singled out by Google, and can you visit it yourself?

Here is everything you need to know about it.

What is Son Doong?

Located within VIetnam’s Phong Nha-Ke Bang National Park, a Unesco World Heritage Site, Son Doong is believed to be one of the biggest natural caves in the world.

It is located close to the border with Laos in central Vietnam, and features an internal, fast-flowing subterranean river, which has carved out a cavern thought to be twice as large as the planet’s next biggest.

It’s estimated to be over 3.8 million square metres in volume, and is so big you could fit an entire New York block of 40-storey buildings inside it - or have a Boeing 747 fly through without its wings clipping the cave walls.

It is estimated that the cave formed between two and five million years ago within its limestone-rich surroundings, but was not discovered until 1991, when it was stumbled upon by a local searching for timber.

The whistling sound of wind and the roar of a rushing stream, as well as the steep descent, discouraged the man from exploring the cave further.

It would be another 18 years before Son Doong was fully mapped by a group of cavers from the British Cave Research Association.

What does it contain?

Scientists have since discovered a wealth of record-breaking geological formations within Son Doong, including the world’s largest limestone pearls and tallest stalagmite.

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.

One of these thriving rainforests is so vast, it even has its own localised weather system.

There’s more to be discovered too - in 2019, a trio of British divers found an underwater tunnel connecting Son Doong to another cave.

Can I visit it?

Son Doong is open to tourists, but permits are required to access the cave.

These are made available only on a limited basis between January and August, as outside of those months, heavy rains can cause river levels to rise, making the cave inaccessible.

The first guided tours of the cave began in 2013, priced at $3,000 (£2,284), and before the pandemic there was a reported one-year waitlist to visit for the mythical Son Doong, such is its popularity.

Plans have been considered in the past to build a cable car system throughout the cave.

But alongside the vast logistical and financial challenges of any such project - the system would be 6.5 miles long, and cost between £85 and £160 million - the plans were opposed by locals because of the damage mass tourism could cause to the cave.