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.

Football transfers are not cheap. To have a player strengthen their ranks, teams are willing to pay big money. The football transfer considered to be the most expensive in the sport's history was that of Gareth Bale leaving Tottenham to play at Real Madrid. The Spanish club paid not less than £86 million (about $133 million at today's exchange rates) to have the player among its own. But recent news suggest that this record might be broken this year. According to reports in the media, UK Premier League team Manchester United is willing to almost double that amount.

Women wearing prosthetic legs participate in a public photo session at the Hasselblad and Profoto booth, during the CP+ camera and imaging equipment trade fair in Yokohama south of Tokyo, February 14, 2015. Japanese prosthetist Fumio Usui inspired the event after collaborating with photographer Takao Ochi in the book project “Amputee Venus” that portrays 11 Japanese women with artificial legs, local media reported. (Photo by Thomas Peter/Reuters)

Two fourteen-week old lion cubs, a male named Ramzes and a female named Zara, are seen during a Christening ceremony at the Bojnice Zoo April 4, 2015. The two cubs are Barbary lions (Panthera leo leo), local media reported. (Photo by Radovan Stoklasa/Reuters)

A body of a victim lies trapped in the debris after an earthquake hit, in Kathmandu, Nepal April 25, 2015. Rescue efforts in Nepal are intensifying after nearly 2,000 people were killed on Saturday in the worst earthquake there in more than 80 years. Many countries and charities have offered aid to deal with the disaster. Seventeen people have been killed on Mount Everest by avalanches – the mountain's worst-ever disaster. Meanwhile a powerful aftershock was felt on Sunday in Nepal, India and Bangladesh, and more avalanches were reported near Everest. (Photo by Navesh Chitrakar/Reuters)

A woman wearing a scarf to cover her face looks on as she waits for a passenger bus on a smoggy morning in New Delhi, India, November 8, 2017. The Great Smog of Delhi is an ongoing severe air-pollution event in New Delhi and adjoining areas in the National Capital Territory of India, in November 2017. Air pollution at this time peaked on both PM 2.5 and PM 10 levels. It has been reported as one of the worst levels of air quality in Delhi since 1999. (Photo by Saumya Khandelwal/Reuters)

A woman cries after her husband was shot dead by unidentified gunmen riding motorcycles in Manila, Philippines late October 10, 2016. According to police reports, around 2,300 people have been killed in Philippine President Rodrigo Duterte's war against illegal drugs. The figure was revised by the police from an original tally of around 3,600 deaths. (Photo by Damir Sagolj/Reuters)

A Taliban helicopter takes off after bringing aid to the site of an earthquake in Gayan, Afghanistan on June 23, 2022. A powerful earthquake struck a rugged, mountainous region of eastern Afghanistan early Wednesday, killing at least 1,000 people and injuring 1,500 more in one of the country's deadliest quakes in decades, the state-run news agency reported. (Photo by Ali Khara/Reuters)