Floating on clear deep water and reflections near the cave entrance. Visitors can either bring their own kayaks or rent boats from the local community to paddle deep inside the cave and marvel at its wonders on March 2015 at Tham Khoun Ex, Laos. Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water. Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water. The cave is formed by the Xe Bang Fai river, a major tributary of the Mekong and in the dry season can be traversed using inflatable kayaks. (Photo by John Spies/Barcroft Media/ABACAPress)

A man admires a sculpture in the series entitled 'Circle of Animals/Zodiac Heads' by Chinese artist Ai Weiwei in the courtyard of Somerset House on May 11, 2011 in London, England. The installation comprises of 12 bronze heads of animals which feature in the Chinese zodiac. The artist Ai Weiwei, who is outspoken in his criticism of the Chinese administration, was detained by authorities in Beijing on April 3, 2011 and his whereabouts remain unknown.

Chinese Artist Ai Weiwei holds some seeds from his Unilever Installation “Sunflower Seeds” at The Tate Modern on October 11, 2010 in London, England. The sculptural installation comprises 100 million handmade porcelain replica sunflower seeds. (Photo by Peter Macdiarmid/Getty Images)

Giant panda Yu Ai enjoys fruit “kebabs” at Chongqing Zoo on November 30, 2024 in Chongqing, China. (Photo by Li Hongbo/VCG via Getty Images)

“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)

Robots of the Zurich Federal Institute of Technology play a football game during the International Telecommunication Union (ITU) AI for Good Global Summit in Geneva on May 30, 2024. (Photo by Fabrice Coffrini/AFP Photo)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

Women jump as they pose for photo in front Patuxay park, ahead of the ASEAN Summit in Vientiane, Laos September 5, 2016. (Photo by Soe Zeya Tun/Reuters)