The world's largest journey through the dark in caves in Vietnam

The expedition 40 people made the journey through Son Doong, the largest natural cave in the world in Quang Binh, Vietnam, exploring the wild and spectacular world inside the cave.

According to National Geographic, Son Doong is the largest natural cave in the world , recorded in 2009. National Geographic photojournalist Martin Edström made the expedition record the magnificent frames of the natural masterpiece inside. Son Doong cave in mid-May 5/2016.

Son Doong Cave was discovered by a local people named Ho Khanh . Anh Khanh also joined the expedition consisting of 40 members of Edström. The goal of the expedition is to collect materials about the exquisite and pristine beauty inside the Son Doong cave before the risk of being transformed by tourism development in the future.

Wonderful space inside Son Doong cave.(Photo: National Geographic).

In order to produce each panoramic photo at a shooting location, the expedition needed to capture up to 400 different frames to stitch together, and it often took several hours to prepare the light before Edström started taking pictures."We use 16 different cameras and use up to 20 kilograms of batteries to turn on the lights that light up the cave," Edström said.

Photos are more difficult to capture and also more impressive as a result of the most unexpected structural features of Son Doong cave. "We walked in the dark, unable to see anything but the lights on our heads and then realized that kilometers away inside the cave, we could see the first light coming into the cave," Edström recalls. ."It was a really exciting moment when you realized you were going through the vast dark cave toward the light."

Light penetrates into Son Doong cave through two huge sinking holes on the ceiling. Scientists estimate these sinkholes formed hundreds of thousands of years ago when the ceiling collapsed. The rivers flow slowly above and at one point in history, the ceiling became too weak to support, create sinkholes and allow sunlight to enter the cave, Edström explained.