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.

These photographs appear to show a spectacular underwater world making it ideal for scuba divers – in central Europe. Twelve metres of water covers trees, footpaths, benches and bridges that are usually accessible throughout the year. Visitors to the Green Lake in Tragoess, Austria, that is normally only one metre deep, can leisurely stroll around the picturesque lagoon. Photo: A diver crossing a bridge in the flood water. (Photo by Solnet/The Grosby Group)

A person waving the rainbow flag runs on the pitch as the players line up for the national anthems the UEFA EURO 2020 Group F football match between Germany and Hungary at the Allianz Arena in Munich on June 23, 2021. (Photo by Alexander Hassenstein/Pool via AFP Photo)

A plane belonging to U.S. missionary group Agape Flights burns after it was set on fire during protests demanding that the government of Prime Minister Ariel Henry do more to address gang violence including constant kidnappings, in Les Cayes, Haiti on March 29, 2022. (Photo by Duples Plymouth/Reuters)

A parrot breeder and his parrots are seen at the Damai Perdana hill in the Cheras region ahead of the May 31 World Parrot Day in Kuala Lumpur, Malaysia on May 29, 2022. A group of parrot breeders in the capital Kuala Lumpur performed a “free flight” performance with different species of parrots. (Photo by Syaiful Redzuan/Anadolu Agency via Getty Images)

Belgium fan wears a devil mask attends the Qatar 2022 World Cup Group F football match between Croatia and Belgium at the Ahmad Bin Ali Stadium in Al-Rayyan, west of Doha on December 1, 2022. (Photo by Stephane Mahe/Reuters)

Men who are part of a neighbourhood vigilante group hold a hammer and machetes while posing for a photograph after suspected gang leader Makandal was killed and set on fire, amid an escalation in gang violence, in Port-au-Prince, Haiti on March 20, 2024. (Photo by Ralph Tedy Erol/Reuters)

This jaw-dropping footage shows one brave diver getting up close and personal with a group of sharks as he feeds them a long-awaited meal. Ken Kiefer from Houston, Texas captured his friend, Jake, reaching right into the mouth of a hammerhead. (Photo by Ken Kiefer/Caters News Agency)