Son doong cave is a cave in Phong Nha-Kẻ Bàng National Park, Bố Trạch district, Quảng Bình Province, Vietnam. Currently the biggest known cave in the world, the cave is located near the Laos-Vietnam border. Inside is a large, fast-flowing underground river.
In early August 2013, the first tourist group explored the cave on a guided tour at a cost of US$3,000 each. The group had six members from Australia, Norway, Russia and USA and spent 7 days and 6 nights for the tour. Next exploration trips will be arranged.

Tim Klingender, Director of Aboriginal Art at Sotheby's hangs the painting “Emu Corroboree Man” by Clifford Possum Tjapaltjarri before a record auction of Aboriginal Art July 14, 2005 in Sydney, Australia. The painting is expected to fetch AUD 150,000 – 250,000 (USD 120,000 – 200,000). Sotheby's unveiled a selection of Aboriginal art and artifacts after a tour of New York and London, which will go to auction in Melbourne July 25 2005. The total pre-sales estimate of the collection is AUD 6 million – 8.5 million (USD 5 million – 7 million). (Photo by Ian Waldie/Getty Images)

WOOTTON, UNITED KINGDOM - APRIL 07: Hot air balloons prepare to depart from Lydden Hill race circuit near Canterbury to take part in mass crossing of the Channel on April 7, 2011 in Wootton, England. 51 balloonists of various nationalities from across Europe took off from Kent making for Calais, France at about 7am. It is the first time a Guinness World Record bid has been made for "the largest group of hot air balloons to make the Channel crossing". (Photo by Oli Scarff/Getty Images)

“The Personal Urban Mobility and Accessibility (PUMA) is an experimental electrically powered road vehicle created by Segway and adopted by General Motors as a concept vehicle representing the future of urban transportation. It operates on two wheels placed side-by-side, a layout that differs in placement from motorcycles which instead have their two wheels placed at the front and rear”. – Wikipedia

The Project P.U.M.A. (Personal Urban Mobility and Accessibility) prototype is displayed for the media April 7, 2009 in New York City. (Photo by Mario Tama/Getty Images)

Yingluck Shinawatra speaks with members of Parliament as the Thai parliament officially elected her as the country's first female Prime Minister August 5, 2011 in Bangkok, Thailand. In the lower house, 296 of the legislature's 500 members voted for Yingluck. Three members voted against and 197 abstained.Thai's cast their ballots back on July 3, 2011. Yingluck Shinawatra, is the younger sister of fugitive former premier Thaksin Shinawatra, who was ousted in a 2006 coup. This is Thailand's 4th election on 7 years as the country continues on a bumpy road to democracy.
(Photo by Paula Bronstein /Getty Images)

“Kavadi Attam is a dance performed by the devotees during the ceremonial worship of Murugan, the Tamil God of War. It is often performed during the festival of Thaipusam and emphasizes debt bondage. The Kavadi itself is a physical burden through which the devotees implore for help from the God Murugan”. – Wikipedia

Photo: A devotee pulls his procession burden connected by hooks pierced in his back during the Thaipusam procession at Sri Srinivasa Perumal Temple on February 7, 2012 in Singapore. (Photo by Chris McGrath/Getty Images)

A face mask is placed on one of the 'Three business men who brought lunch' statues on Swanston street on March 29, 2020 in Melbourne, Australia. All international arrivals into Australia from midnight on Saturday will be placed into mandatory quarantine in hotels for 14 days as the Federal Government increases restrictions to stop the spread of COVID-19. (Photo by Asanka Ratnayake/Getty Images)

A flock of sheep and goats is led by shepherds to pastures at a mountain village on the outskirts of Sana'a, Yemen, 27 July 2023. At least eight million sheep and goats from about 470,000 pastoralist and agro pastoralist households across Yemen will be treated and vaccinated over the two years 2023 and 2024, in an effort to reduce livestock losses, improve production efficiency, and household income generation amid an acute food insecurity, the UN Food and Agriculture Organization (FAO) has reported. (Photo by Yahya Arhab/EPA)