In a reportage entitled “Vietnam Cave” published in the National Geographic magazine in January 2011, M. Jenkin wrote “There is a jungle inside Vietnam’s mammoth cavern.”

The passage to Son Doong Cave is perhaps 300 feet wide, the ceiling nearly 800 feet tall: room enough for an entire New York City block of 40-storey buildings, he wrote, adding that “And the end is out of sight.”

M. Jenkin cited his teammate Jonathan Sims, who was a member of the first expedition to enter the cave, as saying that his team could explore two and a half miles of Son Doong Cave before a 200-foot wall of muddy calcite stopped them. They named it the Great Wall of Vietnam.

Measuring 200m high and 150m wide, the cave, named Son Doong by Khanh who leads a British caving team to explore the cave, is believed to be almost twice the size of the current record holder, Deer Cave in Sarawak Malaysia.

Located in Phong Nha-Ke Bang grotto system, the cave is a limestone region of 2,000km².