The Grotto of Sơn Đoòng is a cave in the province of Quang Binh, Vietnam. It is located in the Phong Nha-Ke Bang National Park.
In April 2009, the existence of a long cavern of 6.5 km, with a preliminary width of 150 m, was revealed to the public in the Vietnamese National Park Phong Nha-Ke Bang.
The Sơn Đoòng Grotto, in Vietnam, was found in February 2009 when a group of British scientists from the British Caves Research Association, led by the couple Howard and Limbert Deb, conducted a survey in Phong Nha-Ke Bang of the 10th to April 14, 2009. A local man had discovered the cave in 1991, but could not remember how to get to it. At the end of March to April 14, 2009, he helped the explorers cross the 10-kilometer forest pass to access the mouth of the cavern.
Years ago, in 1991, a local pastor found her, but, fearing the strange whistle that came from her insides, she kept her location secret. It was used before as a refuge from the bombings in the famous Vietnam War. The first expedition to unravel its secrets was made in 2009 by the couple Howard and Deb Limbert who, however, came across a huge wall of calcite that prevented them from continuing on their way. A local landowner, who knew the entrance, drove the British and German teams to it. According to cavers, the cave is difficult to find because it is completely covered with vegetation.
National Geographic then sent a team to map the cave in 2010, and photographer Carsten Peter got some great photos that came to light in January 2011.