Clay "caganers" representing Spanish Prime Minister Mariano Rajoy (2nd L), Podemos's candidate Pablo Iglesias (R), Socialist Party (PSOE) leader Pedro Sanchez (2nd R) and Ciudadanos party leader Albert Rivera (L) are seen on display at the Santa Llucia Christmas market in central Barcelona, Spain, December 16, 2015. Catalans hide “caganers” or defecators, in Christmas Nativity scenes to let friends hunt for them during Christmas celebrations. The “caganers”, which symbolise defecation and fertilization of the earth, are believed to bring prosperity and luck for the coming year. (Photo by Albert Gea/Reuters)

Actress Demi Moore attends Irving “Swifty” Lazar's Oscar Party hosted at Spago on March 29, 1989 in West Hollywood, California. (Photo by Jim Smeal/WireImage)

In this April 13, 2018 photo, motorcycle taxi driver Ricardo Medina, 60, transports vegetable vender Rigoberto Herrera Mendez, left, and coconut vendor Osvaldo Ochoa in Campo Florido, east of Havana, Cuba. The three men expressed hope that new government leadership will improve things, saying the country cannot move backwards. “We survive life with our work”, said Medina. (Photo by Ramon Espinosa/AP Photo)

A woman controls a ball on Ipanema beach in Rio de Janeiro, Brazil, April 14, 2016. As hundreds of thousands of tourists begin descending on Rio de Janeiro for the Olympics that start August 5, the headlines have focused on the street violence, the Zika virus, the water pollution and the rush to finish venues and transport. But Rio, known by Brazilians as the “Marvelous City”, glistens despite it all. The beach is a way of life here. (Photo by Nacho Doce/Reuters)

It is already one of the world’s most iconic cities, but this incredible collection shows how much Paris has changed over the course of the past century. The collection, by French photographer Julien Knez, shows Paris in the 1940s against a backdrop of how the same places look today. Knez says he put the striking collection together to celebrate the 71st anniversary of the city’s liberation from Nazi control in August 1944. Here: Soldiers outside the Hotel De Ville in the 1940s. (Photo by Julien Knez/Caters News)

Bikini-clad women sit as they operate a 3.6 metre-high custom-made female robot at the “Robot Restaurant” in Kabukicho, one of Tokyo's best known red light districts, August 15, 2012. (Photo by Tokyo Scum Brigade)

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.