Shondong Cave.

Shondong Cave (vietn. hang SơN Đoòng) is an amazing natural attraction that was discovered quite recently. It is located in Central Vietnam (Quang Binh Province) on the territory of the Phong Nha-kẻ Bàng National Park (Phongnya Kebang). From Vietnamese, Sơn Đoòng translates as “cave of the mountain river".Discovery of the Vietnamese Shondong CaveOne day, while walking in the park, a farmer named Ho Han distinctly heard the sound of water and the whistling of the wind. This alerted the man, and he decided to find out what these sounds were. When he reached the place where the roar came from, Ho Han saw the entrance, but since the descent was very steep, the farmer was afraid to go down there. It was in 1991, after which the locals learned about the existence of the cave. But the rest of the world heard about the attraction in 2009 — then Shondong was explored by British speleologists.First of all, the Shondong cave impresses with its size. According to the data available today, the volume inside reaches 38.5 million square meters. m — a building with a height of 40 floors will easily fit here. Inside there are about 150 cave halls, some reach 200 m in height and 150 m in width. Scientists have managed to explore a 6.5 km long section so far. But it is already clear that Shondong is the largest cave in the world.In addition to its impressive size, Shondong has an interesting ecosystem. Scientists have concluded that the age of the cave is 2-5 million years. It arose due to the leaching of limestone rocks by groundwater. And since the cave was inaccessible for many years, a unique microclimate and inner world were formed here.