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 bare-breasted feminist activist bearing a threatening message on her body tried to attack the Russian Orthodox Church's leader Thursday, July 26, 2012, to protest alleged anti-Ukrainian policies by the church and the Kremlin”. – HeraldNet.com

Photo: A topless protester from the Ukrainian feminist group FEMEN is blocked by a security guard and a priest as she tries to throw herself at the leader of the Russian Orthodox Church. (Photo by Associated Press)

Kubra Korkut of Turkey in action against Viktoriia Safonova of the Russian Paralympic Committee during Class 7 Group B Women's Singles Table Tennis Match on day 2 of the Tokyo 2020 Paralympic Games at Tokyo Metropolitan Gymnasium on August 26, 2021 in Tokyo, Japan. (Photo by Ivan Alvarado/Reuters)

Pals let their hair down for one last hoorah in Cardiff, capital of Wales on September 12, 2020. Groups of friends crammed into pubs and restaurants to “go out in style” before the “rule of six” is enforced on Monday. (Photo by Huw Evans Picture Agency/The Sun)

Ferencvaros's David Siger lies on the ground to defend a free kick during the UEFA Champions League Group Stage match between Ferencvarosi TC and Juventus at Puskas Arena on November 4, 2020 in Budapest, Hungary. (Photo by Bernadett Szabo/Reuters)

A driver pulls a handgun on protesters after they broke his trucks lights on March 28, 2021 in Salem, Oregon. The protesters clashed with occupants of vehicles that had participated in an American flag-waving car caravan, despite law enforcements efforts to to keep the groups separate. (Photo by Nathan Howard/Getty Images)

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)