Ambassadors visit Vietnam's majestic cave Son Doong to promote tourism A file photo of explorers inside Son Doong Cave in the central province of Quang Binh. Photo credit: Oxalis A group of ambassadors from several countries began their expedition to Son Doong, believed to be the world's largest cave, on Thursday aiming to promote tourism in central Vietnam.  The ambassadors of Argentina, Australia, Canada, the Czech Republic, Italy, Sweden and the UK are joining the special trip in Quang Binh Province, which will last until May 17. US Assistant Secretary of State Tom Malinowski, Ambassador Pham Sanh Chau of the Foreign Ministry’s Culture and UNESCO Department, and Duong Truong Thien Ly, who represented Vietnam in the Miss World 2008 in South Africa, are among the explorers.  The group will also visit nearby attractions such as En Cave and Phong Nha and camp in the primitive forest. Ho An Phong, director of Quang Binh Department of Culture, Sports and Tourism, said the trip would help promote Quang Binh and Vietnam. Earlier on May 11, the members visited the grave of General Vo Nguyen Giap, a Quang Binh native who commanded Vietnamese forces during Vietnam's revolutionary wars against the French and American armies. He is best known for the stunning victory at Dien Bien Phu in 1954, which ended the French colonization. Giap passed away in Hanoi in  2013 at the age of 92. The ambassadors pay respect to the late General Vo Nguyen Giap (1911-2013) after arriving in Quang Binh on May 11, 2015. Photo: Truong Quang Nam/Thanh Nien Located in the Phong Nha-Ke Bang National Park, the cave of Son Doong was discovered in 1991, but only became internationally recognized in 2009 as the world’s largest natural cave after a group of scientists from the British Cave Research Association conducted a survey in the area. Formed between 2 and 5 million years ago, the cave is 200m high, 150m wide, and some 9km deep with two sinkholes along the ceiling allowing sunlight to enter for the growth of an entire rainforest. In 2015, Quang Binh welcomed nearly 3 million tourists, and the figure is expected to reach 3.5 million this year. So far this year, 216 trekkers have visited Son Doong including 95 Americans and 33 Vietnamese people. A Hollywood crew earlier this year chose Quang Binh as one of the locations to film the much-anticipated King Kong reboot "Kong: Skull Island."  By Truong Quang Nam, Thanh Nien News