Exploring the largest cave – Son Doong

Exploring the largest cave – Son Doong

Visitors to the beautiful landscapes of the Far Eastern jewel of Vietnam are often struck by the country's sheer diversity. Ho Chi Minh City and Hanoi are as bustling and cosmopolitan as anywhere else in the Far East; or, in fact, the world. The Mekong Delta and the bays of Ha Long contain fabulous landscapes. The central Highlands are a wonderful contrast of cultivated land and secretive indigenous villages. But travelling underground often displays Vietnam at its most breathtaking.

For visitors who don't suffer from claustrophobia, exploring below the ground can offer glimpses of a fabulous subterranean world. One particular cave, Son Doong, lay undiscovered for centuries, until a local happened across it. Located near the border with Laos, in Phong Nha-Ke Bang National Park in Quang Binh Province – lying in the portion of the country that was North Korea prior to unification – this cave is the world's largest. As well as being a vast subterranean lair, it also contains a large, fast flowing river.

Its discovery was attributed to a local, named Ho-Khanh, in 1991. This area was actually feared due to the strange whistling sound which persisted (which was eventually attributed to the underground river). Following his finding, researcher arrived from the British Cave Research Association, led by Howard and Deb Limbert. They were surveying the cave in 2009, until their research was cut short by a calcite wall.

That Son Doong was actually discovered to be five times the size of Vietnam's previously largest cave gives some indication of the scale of the 1991 discovery. There are only two known entrances to a chamber estimated at being 9,000 metres in length, and 150 metres wide. Its main chamber is over 200 metres high. A cave exit was discovered in 2010, with the intrepid group who finally scaled the 200-metre high wall discovering pearls ‘the size of baseballs'.

Guided tourists first entered the cave last year, paying $3,000 each for the privilege. These explorers came from the UK, the US, Australia, Norway and Russia. They camped in the dripping cave environment for seven days and six nights. Now that the door to exploration has been opened, future tours will undoubtedly take place on a more regular basis.

The large amount of flowing water inside is something of a hazard for future cavers in Son Doong. Additionally, the entrance to the cave is narrow – it's hardly surprising that its existence wasn't common knowledge until fairly recently.

The new cave was described by the exploratory team's Howard Limbert as ‘a thing of overwhelming beauty and grandeur'. He added that within the cave system, each separate grotto possesses its own beauty, although he was particularly impressed by Ca Xai, a large cave with a lake at its base. This was measured with a 200-metre rope – which didn't reach the lake bed.

Son Doong will not be developed as a tourist destination, in a bid to preserve its natural beauty. However, the existence of fabulous cave systems such as this in Vietnam will only serve to whet the appetite for potholers, cavers and intrepid adventure tourists to seek advice about the whereabouts of Vietnamese caves which are open for business!